1)

Given that $10^{0.48}=x,10^{0.70}=y$ and $x^{2}=y^{2}$, then the value of z is close to:


A) 1.45

B) 1.88

C) 2.9

D) 3.7

Answer:

Option C

Explanation:

$x^{2}=y^{2}$ $\Leftrightarrow \left(10^{0.48}\right)^{z}$ $\Leftrightarrow \left( 10^{0.70}\right)^{2}$ $\Leftrightarrow 10^{0.48z}$ $\Leftrightarrow 10^{2\times 0.70 }$ $\Leftrightarrow 10^{1.40 }$ $\Leftrightarrow 10^{1.40 }$ $\Leftrightarrow z =\frac{140}{48}$ $=\frac{35}{12}$ = 2.9 (approx.).