Last one ... (w+6)^2=3(w+12)-w^2
First, distribute on both sides.w^2+6^2=3w+36-w^2Simplify 6^2.w^2+36=3w+36-w^2Subtract w^2 from both sides.36=3w+36Subtract 36 from both sides.0=3wDivide both sides by 3.0=w