If $2^{(x+y)}= 64$ and $128^{(x-y)} = 2$, then what is the value of $x$? |
41/14 43/14 21/7 22/7 |
43/14 |
The correct answer is Option (2) → 43/14 Given: a. $2^{(x+y)}= 64$ or $2^{(x+y)}= 2^6$ , So, x+y = 6 b. $128^{(x-y)} = 2$ or $(2^7)^{(x-y)} = 2^1$ So, $7(x - y) = 1$ or $x - y = \frac{1}{7}$
Solve the two resulting linear equations: $x + y = 6$ $x - y = \frac{1}{7}$ $2x = 6 + \frac{1}{7}$ $x = \frac{43}{14}$ |