Examples with solutions for Power of a Product: Solving the equation

Exercise #1

(3)584(3)3(3)2(3)5=? \frac{(-3)^5\cdot8^4}{(-3)^3(-3)^2(-3)^{-5}}=\text{?}

Video Solution

Step-by-Step Solution

First, let's recall the law of exponents for multiplication between terms with identical bases:

aman=am+n a^m\cdot a^n=a^{m+n}

and we'll use it to handle the fraction's denominator in the problem:

(3)584(3)3(3)2(3)5=(3)584(3)3+2+(5)=(3)584(3)0 \frac{(-3)^5\cdot8^4}{(-3)^3(-3)^2(-3)^{-5}}=\frac{(-3)^5\cdot8^4}{(-3)^{3+2+(-5)}}=\frac{(-3)^5\cdot8^4}{(-3)^0}

where in the first stage we'll apply the above law to the denominator and then simplify the expression with the exponent in the denominator,

Now let's remember that raising any number to the power of 0 gives the result 1, or mathematically:

X0=1 X^0=1

therefore the denominator we got in the last stage is 1,

meaning we got that:

(3)584(3)3(3)2(3)5=(3)584(3)0=(3)5841=(3)584 \frac{(-3)^5\cdot8^4}{(-3)^3(-3)^2(-3)^{-5}}=\frac{(-3)^5\cdot8^4}{(-3)^0}=\frac{(-3)^5\cdot8^4}{1}=(-3)^5\cdot8^4

Now let's recall the law of exponents for an exponent of a product in parentheses:

(xy)n=xnyn (x\cdot y)^n=x^n\cdot y^n

and we'll apply this law to the first term in the product we got:

(3)584=(13)584=(1)53584=13584=3584 (-3)^5\cdot8^4=(-1\cdot3)^5\cdot8^4 =(-1)^5\cdot3^5\cdot8^4=-1\cdot 3^5\cdot 8^4=-3^5\cdot8^4

Note that the exponent applies separately to both the number 3 and its sign, which is the minus sign that is actually multiplication by 1 -1

Let's summarize everything we did, we got that:

(3)584(3)3(3)2(3)5=(3)584=3584 \frac{(-3)^5\cdot8^4}{(-3)^3(-3)^2(-3)^{-5}}=(-3)^5\cdot8^4 = -3^5\cdot8^4

Therefore the correct answer is answer C.

Answer

3584 -3^5\cdot8^4

Exercise #2

Find the value of x:

1(2×3)2=2x \frac{1}{\left(2\times3\right)^{-2}}=2x

Video Solution

Answer

x=18 x=18

Exercise #3

Find the value of y:

(3×2×4)2=3y \left(3\times2\times4\right)^2=3y

Video Solution

Answer

y=192 y=192