Solve (x+7)^2=y

$$( x + 7 ) ^ { 2 } = y$$

Solve for y

$$y=\left(x+7\right)^{2}$$

Solution Steps

Use binomial theorem \left(a+b\right)^{2}=a^{2}+2ab+b^{2} to expand \left(x+7\right)^{2}.

$$x^{2}+14x+49=y$$

Swap sides so that all variable terms are on the left hand side.

$$y=x^{2}+14x+49$$

Solve for x (complex solution)

$$x=-\left(\sqrt{y}+7\right)$$

$$x=\sqrt{y}-7$$

Solve for x

$$x=-\left(\sqrt{y}+7\right)$$

$$x=\sqrt{y}-7\text{, }y\geq 0$$