Solve 9+x^2=(x+1)^2

$$9 + x ^ { 2 } = ( x + 1 ) ^ { 2 }$$

Solve for x

$$x=4$$

Steps for Solving Linear Equation

Use binomial theorem \left(a+b\right)^{2}=a^{2}+2ab+b^{2} to expand \left(x+1\right)^{2}.

$$9+x^{2}=x^{2}+2x+1$$

Subtract x^{2} from both sides.

$$9+x^{2}-x^{2}=2x+1$$

Combine x^{2} and -x^{2} to get 0.

$$9=2x+1$$

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

$$2x+1=9$$

Subtract 1 from both sides.

$$2x=9-1$$

Subtract 1 from 9 to get 8.

$$2x=8$$

Divide both sides by 2.

$$x=\frac{8}{2}$$

Divide 8 by 2 to get 4.

$$x=4$$