Step-by-step explanation:
AB=28 !... .......hope this helps..

This is equal to...

We want "x" so we need to isolate it using laws of exponents...

because 
because ![x^{a/b}=\sqrt[b]{x^{a}}](https://tex.z-dn.net/?f=x%5E%7Ba%2Fb%7D%3D%5Csqrt%5Bb%5D%7Bx%5E%7Ba%7D%7D)
x = 4
answer: B
Proportional mate try that maybe then
We have,
(2y)^3 × y^-1
Simplify the term (2y)^3
= 8y^3 × y^-1
Now, multiply the terms with the same base y by adding their exponents.
Note: Using exponent product rule x^y × x^z = x^(y+z)
= 8y^{3+(-1)}
= 8y^(3-1)
= 8y^(3-1)
= 8y^2