Examples with solutions for Applying Combined Exponents Rules: Two Variables

Exercise #1

Simplify the expression:

a3a2b4b5= a^3\cdot a^2\cdot b^4\cdot b^5=

Video Solution

Step-by-Step Solution

In the exercise of multiplying powers, we will add up all the powers of the same product, in this case the terms a, b

We use the formula:

an×am=an+m a^n\times a^m=a^{n+m}

We are going to focus on the term a:

a3×a2=a3+2=a5 a^3\times a^2=a^{3+2}=a^5

We are going to focus on the term b:

b4×b5=b4+5=b9 b^4\times b^5=b^{4+5}=b^9

Therefore, the exercise that will be obtained after simplification is:

a5×b9 a^5\times b^9

Answer

a5b9 a^5\cdot b^9

Exercise #2

(a56y)5= (a\cdot5\cdot6\cdot y)^5=

Video Solution

Step-by-Step Solution

We use the formula:

(a×b)x=axbx (a\times b)^x=a^xb^x

Therefore, we obtain:

(a×5×6×y)5=(a×30×y)5 (a\times5\times6\times y)^5=(a\times30\times y)^5

a5305y5 a^530^5y^5

Answer

a5305y5 a^5\cdot30^5\cdot y^5

Exercise #3

(ab8)2= (a\cdot b\cdot8)^2=

Video Solution

Step-by-Step Solution

We use the formula

(a×b)x=axbx (a\times b)^x=a^xb^x

Therefore, we obtain:

a2b282 a^2b^28^2

Answer

a2b282 a^2\cdot b^2\cdot8^2

Exercise #4

ababa2 a\cdot b\cdot a\cdot b\cdot a^2

Video Solution

Step-by-Step Solution

We use the power property to multiply terms with identical bases:

aman=am+n a^m\cdot a^n=a^{m+n} It is important to note that this property is only valid for terms with identical bases,

We return to the problem

We notice that in the problem there are two types of terms with different bases. First, for the sake of order, we will use the substitution property of multiplication to rearrange the expression so that the two terms with the same base are grouped together. Then, we will proceed to work:

ababa2=aaa2bb a\cdot b\operatorname{\cdot}a\operatorname{\cdot}b\operatorname{\cdot}a^2=a\cdot a\cdot a^2\cdot b\cdot b Next, we apply the power property for each type of term separately,

aaa2bb=a1+1+2b1+1=a4b2 a\cdot a\cdot a^2\cdot b\cdot b=a^{1+1+2}\cdot b^{1+1}=a^4\cdot b^2

We apply the power property separately - for the terms whose bases area a and then for the terms whose bases areb b and we add the exponents and simplify the terms.

Therefore, the correct answer is option c.

Note:

We use the fact that:

a=a1 a=a^1 and the same for b b .

Answer

a4b2 a^4\cdot b^2

Exercise #5

k2t4k6t2= k^2\cdot t^4\cdot k^6\cdot t^2=

Video Solution

Step-by-Step Solution

Using the power property to multiply terms with identical bases:

aman=am+n a^m\cdot a^n=a^{m+n} It is important to note that this law is only valid for terms with identical bases,

We notice that in the problem there are two types of terms. First, for the sake of order, we will use the substitution property to rearrange the expression so that the two terms with the same base are grouped together. The, we will proceed to solve:

k2t4k6t2=k2k6t4t2 k^2t^4k^6t^2=k^2k^6t^4t^2 Next, we apply the power property to each different type of term separately,

k2k6t4t2=k2+6t4+2=k8t6 k^2k^6t^4t^2=k^{2+6}t^{4+2}=k^8t^6 We apply the property separately - for the terms whose bases arek k and for the terms whose bases aret t We add the powers in the exponent when we multiply all the terms with the same base.

The correct answer then is option b.

Answer

k8t6 k^8\cdot t^6

Exercise #6

(y×x×3)5= (y\times x\times3)^5=

Video Solution

Step-by-Step Solution

We use the formula:

(a×b)n=anbn (a\times b)^n=a^nb^n

(y×x×3)5=y5x535 (y\times x\times3)^5=y^5x^53^5

Answer

y5×x5×35 y^5\times x^5\times3^5

Exercise #7

1an=? \frac{1}{a^n}=\text{?}

a0 a\ne0

Video Solution

Step-by-Step Solution

This question is actually a proof of the law of exponents for negative exponents, we will prove it simply using two other laws of exponents:

a. The zero exponent law, which states that raising any number to the power of 0 (except 0) will give the result 1:

X0=1 X^0=1

b. The law of exponents for division between terms with identical bases:

bmbn=bmn \frac{b^m}{b^n}=b^{m-n}

Let's return to the problem and pay attention to two things, the first is that in the denominator of the fraction there is a term with base a a and the second thing is that according to the zero exponent law mentioned above in a' we can always write the number 1 as any number (except 0) to the power of 0, particularly in this problem, given that a0 a\neq0 we can claim that:

1=a0 1=a^0

Let's apply this to the problem:

1an=a0an \frac{1}{a^n}=\frac{a^0}{a^n}

Now that we have in the numerator and denominator of the fraction terms with identical bases, we can use the law of division between terms with identical bases mentioned in b' in the problem:

a0an=a0n=an \frac{a^0}{a^n}=a^{0-n}=a^{-n}

Let's summarize the steps above, we got that:

1an=a0an=an \frac{1}{a^n}=\frac{a^0}{a^n}=a^{-n}

In other words, we proved the law of exponents for negative exponents and understood why the correct answer is answer c.

Answer

an a^{-n}

Exercise #8

xa=? x^{-a}=\text{?}

Video Solution

Step-by-Step Solution

We use the exponential property of a negative exponent:

bn=1bn b^{-n}=\frac{1}{b^n} We apply it to the problem:

xa=1xa x^{-a}=\frac{1}{x^a} Therefore, the correct answer is option C.

Answer

1xa \frac{1}{x^a}

Exercise #9

((4x)3y)2= ((4x)^{3y})^2=

Video Solution

Step-by-Step Solution

We'll use the power rule for powers:

(am)n=amn (a^m)^n=a^{m\cdot n} We'll apply this rule to the expression in the problem:

((4x)3y)2=(4x)3y2=(4x)6y ((4x)^{3y})^2= (4x)^{3y\cdot2}=(4x)^{6y} When in the first stage we applied the mentioned power rule and eliminated the outer parentheses, in the next stage we simplified the resulting expression,

Next, we'll recall the power rule for powers that applies to parentheses containing a product of terms:

(ab)n=anbn (a\cdot b)^n=a^n\cdot b^n We'll apply this rule to the expression we got in the last stage:

(4x)6y=46yx6y (4x)^{6y} =4^{6y}\cdot x^{6y} When we applied the power to the parentheses to each term of the product inside the parentheses.

Therefore, the correct answer is answer D.

Answer

46yx6y 4^{6y}\cdot x^{6y}