Question

I’m confused on this

Answer 1

$\huge\boxed{x=25}$

The mistake is in Step 1. The solver should have also squared $9$ when squaring the other side of the equation.

Correctly solving

$\begin{aligned}\sqrt{3x+6}&=9\\(\sqrt{3x+6})^2&=9^2\\3x+6&=81\\3x+6-6&=81-6\\3x&=75\\\frac{3x}{3}&=\frac{75}{3}\\x&=25\end{aligned}$

Answer 2

Answer:

x = 25

Step-by-step explanation:

The mistake here is the squaring. When you square one side, you have to do the same on the other side:

$\sqrt{3x+6}$ = 9

$(\sqrt{3x+6}) ^{2}$ = $9^{2}$

3x + 6 = 81

3x = 75

x = 25