Question

 rút gọn biểu thức 5(x+2)(x-2) -(2x-3)^2 -x^2+17

Answer 1

\(5\left(x+2\right)\left(x-2\right)-\left(2x-3\right)^2-x^2+17=5\left(x^2-4\right)-\left(4x^2-12x+9\right)-x^2+17=12x-12\)

Answer 2

5(x+2)(x−2)−(2x−3)2−x2+17(x2−4)−(4x2−12x+9)−x2+17=12x−12

Answer 3

\(5\left(x+2\right)\left(x-2\right)-\left(2x-3\right)^2-x^2+17\)

\(=5x^2-20-4x^2+12x-9-x^2+17\)

=12x-12