### Home > PC > Chapter 3 > Lesson 3.3.2 > Problem3-122

3-122.

Estimate the solution to each of these equations without a calculator and justify your estimate. Then solve them to the nearest $0.001$.

1.  $20^x=316$

Since $20^2=400$, $x$ must be less than $2$.

1.  $7.3^x=4.81$

$7.3^1=7.3$, so $x$ must be less than $1$.

1.  $160(0.5)^x=8$

$\left(\frac{1}{2}\right)^x=\frac{8}{160}=\frac{1}{20}$

$\left(\frac{1}{2}\right)^4=\frac{1}{16}$