Examples with solutions for Additional Arithmetic Rules: Using variables

Exercise #1

x(yx)=? x-(y-x)=\text{?}

Video Solution

Step-by-Step Solution

First, we address the parenthesis:

Remember that:

When we multiply a positive number by a negative number, the result will be negative.

When we multiply a negative number by a negative number, the result will be positive.

We obtain the following:

xy+x= x-y+x=

We join the x coefficients:

x+x=2x x+x=2x

Lastly we obtain:

2xy 2x-y

Answer

2xy 2x-y

Exercise #2

7x(4b+3x)=? 7x-(4b+3x)=\text{?}

Video Solution

Step-by-Step Solution

First, we open the parentheses and change the sign accordingly.

Since there are only positive numbers inside the parentheses, multiplying by minus will give us negative numbers:

7x4b3x= 7x-4b-3x=

Now we group the X factors:

7x3x=4x 7x-3x=4x

Now we obtain:

4x4b 4x-4b

Answer

4x4b 4x-4b

Exercise #3

10y(5y+3z)=? 10y-(5y+3z)=\text{?}

Video Solution

Step-by-Step Solution

First, we open the parentheses and change the sign accordingly.

Since there are only positive numbers inside the parentheses, multiplying by the minus will give us negative numbers:

10y5y3z= 10y-5y-3z=

Now we group the Y factors:

10y5y=5y 10y-5y=5y

Now we obtain:

5y3z 5y-3z

Answer

5y3z 5y-3z

Exercise #4

x(3x+4y)=? x-(3x+4y)=\text{?}

Video Solution

Step-by-Step Solution

First, we open the parentheses and change the sign accordingly.

Since there are only positive numbers within the parentheses, multiplying by a negative will give us negative numbers:

x3x4y= x-3x-4y=

Now we group the X factors:

x3x=2x x-3x=-2x

We obtain:

2x4y -2x-4y

Answer

2x4y -2x-4y

Exercise #5

12a/(7x4b)=? 12a/(7x\cdot4b)=\text{?}

Video Solution

Step-by-Step Solution

Let's begin by writing the exercise as a fraction:

12a7x×4b= \frac{12a}{7x\times4b}=

Next we'll factor the numerator of the fraction into a smaller multiplication exercise:

4×3a7x×4b= \frac{4\times3a}{7x\times4b}=

Let's now reduce the 4 in both the numerator and denominator of the fraction:

3a7xb \frac{3a}{7xb}

Answer

3a7xb \frac{3a}{7xb}

Exercise #6

a:4a=? a:\frac{4}{a}=\text{?}

Video Solution

Step-by-Step Solution

Let's flip the fraction to get a multiplication exercise:

a×a4= a\times\frac{a}{4}=

We'll add the a to the numerator of the fraction:

a×a4=a24 \frac{a\times a}{4}=\frac{a^2}{4}

Answer

a24 \frac{a^2}{4}

Exercise #7

Simplify the following expression:

3m12n/(7m4n)=? 3m\cdot12n/(7m\cdot4n)=\text{?}

Video Solution

Step-by-Step Solution

Let's write the exercise as a fraction:

3m×12n7m×4n= \frac{3m\times12n}{7m\times4n}=

Let's reduce between the m in the numerator and the n in the denominator:

3×127×4= \frac{3\times12}{7\times4}=

Let's write the 12 in the numerator of the fraction as a smaller multiplication exercise:

3×4×37×4= \frac{3\times4\times3}{7\times4}=

Let's reduce between the 4 in the numerator and the denominator:

3×37=97=127 \frac{3\times3}{7}=\frac{9}{7}=1\frac{2}{7}

Answer

127 1\frac{2}{7}

Exercise #8

5x2/(3y20x)=? 5x^2/(3y\cdot20x)=\text{?}

Video Solution

Step-by-Step Solution

Let's write the exercise as a fraction:

5x23y×20x= \frac{5x^2}{3y\times20x}=

We'll factor the numerator of the fraction into a multiplication exercise:

5x×x3y×20x= \frac{5x\times x}{3y\times20x}=

Let's write the 20 in the denominator of the fraction as a smaller multiplication exercise:

5x×x3y×4×5x= \frac{5x\times x}{3y\times4\times5x}=

We'll cancel out the 5x in both the numerator and denominator of the fraction:

x3y×4= \frac{x}{3y\times4}=

Let's multiply the denominator of the fraction:

x12y \frac{x}{12y}

Answer

x12y \frac{x}{12y}

Exercise #9

x:(xy)=? x:(x\cdot y)=\text{?}

Video Solution

Step-by-Step Solution

Let's write the expression as a fraction:

xx×y= \frac{x}{x\times y}=

We'll reduce between the x in the numerator and denominator and get:

1y \frac{1}{y}

Answer

1y \frac{1}{y}

Exercise #10

14a/(2a3a)=? 14a/(2a\cdot3a)=\text{?}

Video Solution

Step-by-Step Solution

The problem asks us to simplify the expression 14a2a3a\frac{14a}{2a \cdot 3a}.

First, simplify the expression in the denominator:

  • The denominator 2a3a2a \cdot 3a can be expanded by multiplying the constants and variables separately: 23aa=6a22 \cdot 3 \cdot a \cdot a = 6a^2.

Now, the expression becomes:

  • 14a6a2\frac{14a}{6a^2}

Next, simplify the fraction by canceling out common factors in the numerator and the denominator:

  • Both the numerator and the denominator contain the variable aa. We can divide both by aa, resulting in:
  • 146a\frac{14}{6a}

Further simplify the fraction by dividing both the numerator and the denominator by their greatest common divisor, which is 2:

  • 14÷26÷2a=73a\frac{14 \div 2}{6 \div 2a} = \frac{7}{3a}

Thus, the simplified form of the expression is 73a\frac{7}{3a}.

Therefore, the solution to the problem is 73a\frac{7}{3a}.

Answer

73a \frac{7}{3a}

Exercise #11

32m:(8t:3m)=? 32m:(8t:3m)=\text{?}

Video Solution

Step-by-Step Solution

To solve this problem, follow these steps:

  • Step 1: Simplify the inner division 8t:3m8t : 3m. This can be rewritten as 8t3m\frac{8t}{3m}.
  • Step 2: Find the reciprocal of 8t3m\frac{8t}{3m}. The reciprocal is 3m8t\frac{3m}{8t}.
  • Step 3: Multiply 32m32m by the reciprocal of the inner division result, which is 3m8t\frac{3m}{8t}.

Carrying out the multiplication:

32m×3m8t=32m×3m8t=96m28t32m \times \frac{3m}{8t} = \frac{32m \times 3m}{8t} = \frac{96m^2}{8t}

Simplify the expression 96m28t\frac{96m^2}{8t} by dividing the numerator and the denominator by 8:

=12m2t= \frac{12m^2}{t}

Thus, the final simplified solution is 12m2t12\frac{m^2}{t}.

The correct choice from the given options is 12m2t12\frac{m^2}{t}.

Answer

12m2t 12\frac{m^2}{t}

Exercise #12

2x:(7y:4x)=? 2x:(7y:4x)=\text{?}

Video Solution

Step-by-Step Solution

To solve this problem, we'll simplify the expression 2x:(7y:4x) 2x : (7y : 4x) using properties of division:

  • Step 1: Recognize a:(b:c)=a×cb a : (b : c) = a \times \frac{c}{b} . This changes the nested division into a singular operation.
  • Step 2: Substitute into our expression: 2x:(7y:4x)=2x×4x7y 2x : (7y : 4x) = 2x \times \frac{4x}{7y} .
  • Step 3: Simplify the expression =2×4x27y = 2 \times \frac{4x^2}{7y} .
  • Step 4: Calculate the product: =8x27y = \frac{8x^2}{7y} .
  • Step 5: Convert to a mixed number if necessary: =117x2y = 1\frac{1}{7}\frac{x^2}{y} .

Therefore, the solution to the problem is 8x27y \frac{8x^2}{7y} , which can be expressed as a mixed number 117x2y 1\frac{1}{7}\frac{x^2}{y} .

Answer

117x2y 1\frac{1}{7}\frac{x^2}{y}

Exercise #13

2a+3b(4b3a)=? 2a+3b-(4b-3a)=\text{?}

Video Solution

Step-by-Step Solution

We begin by addressing the parenthesis first:

Remember that:

When we multiply a positive number by a negative number, the result will be negative.

When we multiply a negative number by a negative number, the result will be positive.

Hence we obtain the following calculation:

2a+3b4b+3a= 2a+3b-4b+3a=

We join together the a coefficients:

2a+3a=5a 2a+3a=5a

We then join together the b coefficients:

3b4b=b 3b-4b=-b

We obtain the following:

5ab 5a-b

Answer

5ab 5a-b

Exercise #14

a+b(ab)=? a+b-(a-b)=\text{?}

Video Solution

Step-by-Step Solution

We begin by addressing the parenthesis first:

Remember that:

When we multiply a positive number by a negative number the result will be negative.

When we multiply a negative number by a negative number the result will be positive.

Hence we obtain the following calculation:

a+ba+b= a+b-a+b=

Next we join together the a coefficients:

aa=0 a-a=0

We then join together the b coefficients:

b+b=2b b+b=2b

We obtain the following:

0+2b=2b 0+2b=2b

Answer

2b 2b

Exercise #15

3m14n(7m3n)=? 3m-14n-(7m-3n)=\text{?}

Video Solution

Step-by-Step Solution

We begin by addressing the parenthesis first:

Remember that:

When we multiply a positive number by a negative number the result will be negative.

When we multiply a negative number by a negative number the result will be positive.

Thus we obtain the following equation:

3m14n7m+3n= 3m-14n-7m+3n=

Next we join the m coefficients:

3m7m=4m 3m-7m=-4m

We then join the n coefficients:14n+3n=11n -14n+3n=-11n

Finally we obtain:

4m11n -4m-11n

Answer

4m11n -4m-11n

Exercise #16

12z+3m(mz)=? 12z+3m-(m-z)=\text{?}

Video Solution

Step-by-Step Solution

We begin by addressing the parenthesis:

Remember that:

When we multiply a positive number by a negative number, the result will be negative.

When we multiply a negative number by a negative number, the result will be positive.

Hence we obtain the following calculation:

12z+3mm+z= 12z+3m-m+z=

Next we join together the z coefficients:

12z+z=13z 12z+z=13z

We then join together the m coefficients:

3mm=2m 3m-m=2m

Finally we obtain the following:

13z+2m 13z+2m

Answer

13z+2m 13z+2m

Exercise #17

Solve the following problem:

(a+b):(3/4)=? (a+b):(3/4)=\text{?}

Video Solution

Step-by-Step Solution

Begin by writing the exercise as a fraction:

(a+b):34= (a+b):\frac{3}{4}=

Proceed to write the fraction in reverse order for the purpose of obtaining a multiplication exercise:

(a+b)×43= (a+b)\times\frac{4}{3}=

Finally we obtain the following result:

43(a+b) \frac{4}{3}(a+b)

Answer

43(a+b) \frac{4}{3}(a+b)

Exercise #18

Solve the following equation:

3x/(2t4z)=? 3x/(2t\cdot4z)=\text{?}

Video Solution

Step-by-Step Solution

First let's rewrite the expression as a fraction:

3x2t×4z= \frac{3x}{2t\times4z}=

We should note that since there is only a multiplication operation in the numerator of the fraction, we will multiply the coefficients together:

3x2×4×t×z=3x8tz \frac{3x}{2\times4\times t\times z}=\frac{3x}{8tz}

Answer

3x8tz \frac{3x}{8tz}

Exercise #19

Simplify the following expression:

xyz/(3x4y5z)=? x\cdot y\cdot z/(3x\cdot4y\cdot5z)=\text{?}

Video Solution

Step-by-Step Solution

First let's write the exercise as a fraction:

x×y×z3x×4y×5z= \frac{x\times y\times z}{3x\times4y\times5z}=

Then we'll cancel out the x, the Y, and the z from both the numerator and denominator of the fraction:

13×4×5= \frac{1}{3\times4\times5}=

Then, we'll multiply the expression in the denominator from left to right:

13×4×5=112×5=160 \frac{1}{3\times4\times5}=\frac{1}{12\times5}=\frac{1}{60}

Answer

160 \frac{1}{60}

Exercise #20

a+b+c(abc)=? a+b+c-(a-b-c)=\text{?}

Video Solution

Step-by-Step Solution

Firstly we need to look at the expression inside of parentheses.

Remember:

When we multiply a negative number by a negative number, the result will be positive.

When we multiply a positive number by a negative number, the result will be negative.

Therefore:

a+b+ca+b+c= a+b+c-a+b+c=

Now let's combine the a a terms:

aa=0 a-a=0

Then we can combine the b b terms:

b+b=2b b+b=2b

Finally let's combine the c c terms:

c+c=2c c+c=2c

This leaves us with:

0+2b+2c=2b+2c 0+2b+2c=2b+2c

Answer

2b+2c 2b+2c