Question

descompuneti in factori expresiile:
a) 16(2x-7)la a doua - 9(x-3)la a doua
b)x la a treia-9x la a doua - 9x+81 Helpppppp

Answer 1

a) 16(2x-7)² -9(x-3)² = [4(2x-7) +3(x-3)]× [4(2x-7) -3(x-3)]=
=(8x -28 +3x-9)(8x -28-3x +3) = (11x-37)(5x-25) = 5(x-5)(11x-37)

b) x³ -9x² -9x +81 = x² (x-9) -9(x-9) = (x-9) (x²-9) = (x-9)(x+3)(x-3)

c) x² -5x -24= x² -8x +3x -24 = x(x-8) +3(x-8) = (x-8)(x+3)