If 3x-12=y, what is the value of 8 to the x power over 2 to the y power?

Question

If 3x-12=y, what is the value of 8^x÷2^y?

A) 2¹²

B) 4⁴

C) 8²

D) The value cannot be determined from the information given.

Answer 1

We have y = 3x + 12 and

8^x / 2^{(3x + 12)} = 2^3x / 2^3x 2¹² = 1 / 2¹² = 1 / 4096

Answer 2

Get 8^x/2^y in terms of x.

8^x/2^3x-12

Now get common bases.

2^3x/2^3x-12

When you divide like bases, you subtract the exponents.

3x - (3x - 12) = 3x - 3x +12 = 12

So the answer is A 2¹²