Question

sendo A=x-3; B=x²+3 e C=9x, o valor de A²-B+C é?

Answer 1

$A=x-3; B=x^2+3; C=9x \\ \\ A^2 - B + C = \\ (x - 3)^2 - (x^2 + 3) + (9x) = \\ x^2 - 6x + 9 - x^2 - 3 + 9x = \\ x^2 - x^2 - 6x + 9x + 9 - 3 = 3x + 6$