Answer
{$-\frac{2}{7},-\frac{4}{7}$}
Work Step by Step
We know that if $x^{2}=a$, then $x=\pm \sqrt{a}$. Thus, we obtain:
Step 1: $(7x+3)^{2}=1$
Step 2: $7x+3=\pm \sqrt {1}$
Step 3: $7x+3=\pm 1$
Step 4: $7x=-3\pm 1$
Step 5: $x=\frac{-3\pm 1}{7}$
Step 6: $x=\frac{-3+ 1}{7}$ or $x=\frac{-3-1}{7}$
Step 7: $x=\frac{-2}{7}$ or $x=\frac{-4}{7}$
Therefore, the solution set is {$-\frac{2}{7},-\frac{4}{7}$}.
