Question

Calcule o valor numérico de 9x²-18xb+9b², para x-b = 5

Answer 1

$9x^2 - 18bx+9b^2 = 9(x-b)^2 \\ \\ 9x^2 - 18bx+9b^2 = 9.5^2 \\ \\ 9x^2 - 18bx+9b^2 = 9.25 \\ \\ 9x^2 - 18bx+9b^2 = 225$

Answer 2

9.5²-18.5.5+9.5²
225-450+225
225-225
0