Two numbers are multiplicative inverses when their product results in 1 1 .

For example:

12{\Large {1 \over 2}} and 2 2 are multiplicative inverses because 212=1{\Large 2 \cdot {1 \over 2}=1}

Formulation of the Rule for Multiplicative Inverse Numbers:

Whenever a is different from 00, it follows that a1a=1{\Large a\cdot{1 \over a} = 1}

Multiplicative Inverse

Multiplication and Division of Multiplicative Inverses

Division is equivalent to multiplication by its multiplicative inverse,

That is:  213=23=6{\Large {{2 \over {1 \over 3}} = 2 \cdot 3 = 6}}

Because 3 3 is the multiplicative inverse of  13{\Large {1 \over 3}}

Generally: a1b=ab \frac{a}{\frac{1}{b}}=a⋅b

Suggested Topics to Practice in Advance

  1. The Order of Basic Operations: Addition, Subtraction, and Multiplication
  2. Order of Operations: Exponents
  3. Order of Operations: Roots
  4. Order of Operations with Parentheses

Practice Multiplicative Inverse

Examples with solutions for Multiplicative Inverse

Exercise #1

8×(5×1)= 8\times(5\times1)=

Video Solution

Step-by-Step Solution

According to the order of operations, we first solve the expression in parentheses:

5×1=5 5\times1=5

Now we multiply:

8×5=40 8\times5=40

Answer

40

Exercise #2

7×1+12= 7\times1+\frac{1}{2}=

Video Solution

Step-by-Step Solution

According to the order of operations rules, we first insert the multiplication exercise into parentheses:

(7×1)+12= (7\times1)+\frac{1}{2}=

Let's solve the exercise inside the parentheses:

7×1=7 7\times1=7

And now we get the exercise:

7+12=712 7+\frac{1}{2}=7\frac{1}{2}

Answer

712 7\frac{1}{2}

Exercise #3

63×1= \frac{6}{3}\times1=

Video Solution

Step-by-Step Solution

According to the order of operations rules, we will solve the exercise from left to right, since there are only multiplication and division operations:

63=2 \frac{6}{3}=2

2×1=2 2\times1=2

Answer

2 2

Exercise #4

(3×515×1)+32= (3\times5-15\times1)+3-2=

Video Solution

Step-by-Step Solution

This simple rule is the order of operations which states that exponentiation precedes multiplication and division, which precede addition and subtraction, and that operations enclosed in parentheses precede all others,

Following the simple rule, multiplication comes before division and subtraction, therefore we calculate the values of the multiplications and then proceed with the operations of division and subtraction

35151+32=1515+32=1 3\cdot5-15\cdot1+3-2= \\ 15-15+3-2= \\ 1 Therefore, the correct answer is answer B.

Answer

1 1

Exercise #5

(5×410×2)×(35)= (5\times4-10\times2)\times(3-5)=

Video Solution

Step-by-Step Solution

This simple rule is the order of operations which states that multiplication precedes addition and subtraction, and division precedes all of them,

In the given example, a multiplication occurs between two sets of parentheses, thus we simplify the expressions within each pair of parentheses separately,

We start with simplifying the expression within the parentheses on the left, this is done in accordance with the order of operations mentioned above, meaning that multiplication comes before subtraction, we perform the multiplications in this expression first and then proceed with the subtraction operations within it, in reverse we simplify the expression within the parentheses on the right and perform the subtraction operation within them:

What remains for us is to perform the last multiplication that was deferred, it is the multiplication that occurred between the expressions within the parentheses in the original expression, we perform it while remembering that multiplying any number by 0 will result in 0:

Therefore, the correct answer is answer d.

Answer

0 0

Exercise #6

(5+43)2:(5×210×1)= (5+4-3)^2:(5\times2-10\times1)=

Video Solution

Step-by-Step Solution

This simple rule is the order of operations which states that exponentiation precedes multiplication and division, which precede addition and subtraction, and that operations enclosed in parentheses precede all others,

In the given expression, the establishment of division between two sets of parentheses, note that the parentheses on the left indicate strength, therefore, in accordance to the order of operations mentioned above, we start simplifying the expression within those parentheses, and as we proceed, we obtain the result derived from simplifying the expression within those parentheses with given strength, and in the final step, we divide the result obtained from the simplification of the expression within the parentheses on the right,

We proceed similarly with the simplification of the expression within the parentheses on the left, where we perform the operations of multiplication and division, in strength, in contrast, we simplify the expression within the parentheses on the right, which, according to the order of operations mentioned above, means multiplication precedes division, hence we first perform the operations of multiplication within those parentheses and then proceed with the operation of division:

(5+43)2:(52101)=(2)2:(1010)=4:0 (5+4-3)^2:(5\cdot2-10\cdot1)= \\ (-2)^2:(10-10)= \\ 4:0\\ We conclude that the sequence of operations within the expression that is within the parentheses on the left yields a smooth result, this result we leave within the parentheses, these we raised in the next step in strength, this means we remember that every number (positive or negative) in dual strength gives a positive result,

As we proceed, note that in the last expression we received from establishing division by the number 0, this operation is known as an undefined mathematical operation (and this is the simple reason why a number should never be divided by 0 parts) therefore, the given expression yields a value that is not defined, commonly denoted as "undefined group" and use the symbol :

{} \{\empty\} In summary:

4:0={} 4:0=\\ \{\empty\} Therefore, the correct answer is answer A.

Answer

No solution

Exercise #7

Solve the following exercise:

12+30= 12+3\cdot0=

Step-by-Step Solution

According to the order of operations, we first multiply and then add:

12+(30)= 12+(3\cdot0)=

3×0=0 3\times0=0

12+0=12 12+0=12

Answer

12 12

Exercise #8

Solve the following exercise:

2+0:3= 2+0:3=

Step-by-Step Solution

According to the order of operations rules, we first divide and then add:

2+(0:3)= 2+(0:3)=

0:3=0 0:3=0

2+0=2 2+0=2

Answer

2 2

Exercise #9

25+2510= \frac{25+25}{10}=

Video Solution

Step-by-Step Solution

Let's begin by multiplying the numerator:

25+25=50 25+25=50

We obtain the following fraction:

5010 \frac{50}{10}

Finally let's reduce the numerator and denominator by 10 and we are left with the following result:

51=5 \frac{5}{1}=5

Answer

5 5

Exercise #10

0:7+1= 0:7+1=

Video Solution

Step-by-Step Solution

According to the order of operations rules, we first divide and then add:

0:7=0 0:7=0

0+1=1 0+1=1

Answer

1 1

Exercise #11

12+1+0= 12+1+0=

Video Solution

Step-by-Step Solution

According to the order of operations rules, since the exercise only involves addition operations, we will solve the problem from left to right:

12+1=13 12+1=13

13+0=13 13+0=13

Answer

13

Exercise #12

0+0.2+0.6= 0+0.2+0.6=

Video Solution

Step-by-Step Solution

According to the order of operations rules, since the exercise only involves addition operations, we will solve the problem from left to right:

0+0.2=0.2 0+0.2=0.2

0.2+0.6=0.8 0.2+0.6=0.8

Answer

0.8

Exercise #13

12+0+12= \frac{1}{2}+0+\frac{1}{2}=

Video Solution

Step-by-Step Solution

According to the order of operations, since the exercise only involves addition operations, we will solve the problem from left to right:

12+0=12 \frac{1}{2}+0=\frac{1}{2}

12+12=11=1 \frac{1}{2}+\frac{1}{2}=\frac{1}{1}=1

Answer

1 1

Exercise #14

90+0.5= 9-0+0.5=

Video Solution

Step-by-Step Solution

According to the order of operations rules, since the exercise only involves addition and subtraction, we will solve the problem from left to right:

90=9 9-0=9

9+0.5=9.5 9+0.5=9.5

Answer

9.5

Exercise #15

19+10= 19+1-0=

Video Solution

Step-by-Step Solution

According to the order of operations rules, since the exercise only involves addition and subtraction operations, we will solve the problem from left to right:

19+1=20 19+1=20

200=20 20-0=20

Answer

20 20

Topics learned in later sections

  1. Division and Fraction Bars (Vinculum)
  2. The Numbers 0 and 1 in Operations
  3. Neutral Element (Identiy Element)
  4. The Order of Operations
  5. Order or Hierarchy of Operations with Fractions