Question

Solve for x and y.

4^(x+y) = 64

2^(2x-y) = 128


A) x = 10/3, y = -1/3
B) x = -10/3, y = -1/3

Answer 1

`4^(x+y)=64\Rightarrow x+y=3`

`2^(2x-y)=128\Rightarrow 2x-y=7`

So we have

`x+y=3`

`2x-y=7`
Solve for
`x`:

`3x=10`

`\Rightarrow x=(10)/(3)`

Plug
`x` into one of the equations:

`(10)/(3)+y=3`

`\Rightarrow y=-(1)/(3)`

So the answer is

`x=(10)/(3), y=-(1)/(3)`

Answer 2

4^10/3 + -1/3 will equal to 64
2^(2*10/3-1/3) will equal to 128

Your final answer is A. x = 10/3, y = -1/3