Solve 12^2+x^2=(18-x)^2

$$12 ^ { 2 } + x ^ { 2 } = ( 18 - x ) ^ { 2 }$$

Solve for x

$$x=5$$

Steps for Solving Linear Equation

Calculate 12 to the power of 2 and get 144.

$$144+x^{2}=\left(18-x\right)^{2}$$

Use binomial theorem \left(a-b\right)^{2}=a^{2}-2ab+b^{2} to expand \left(18-x\right)^{2}.

$$144+x^{2}=324-36x+x^{2}$$

Add 36x to both sides.

$$144+x^{2}+36x=324+x^{2}$$

Subtract x^{2} from both sides.

$$144+x^{2}+36x-x^{2}=324$$

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

$$144+36x=324$$

Subtract 144 from both sides.

$$36x=324-144$$

Subtract 144 from 324 to get 180.

$$36x=180$$

Divide both sides by 36.

$$x=\frac{180}{36}$$

Divide 180 by 36 to get 5.

$$x=5$$