Question

Descompuneti in factori aplicand formula:a²-b²=(a+b)(a-b):

a)x²-4(x-3)²
b)9x²-(3x+4)²
Si am una rezolvata aici:
d)16(3x-2)²-25x²=(12x-8-5x)(12x-8+5x)=(7x-8)(17x-8)
Sper sa ma puteti ajuta, va rog!!

Answer 1

a)[x-4(x-3)][x+4(x-3)]= (x-4x+12)(x+4x-12)=(-3x+12)(5x-12)=3(-x+4)(5x-12)

b)[3x-(3x+4)][3x+(3x+4)]= (3x-3x+4)(3x+3x+4)= 4(6x+4)= 4*2(3x+2)= 8(3x+2)

Answer 2

x²-4(x-3)² =x²-4(x²-6x+9)
               =x²-4x²+24x-36
               =24x-3x²-36
b))9x²-(3x+4)²
(9x-3x+4)(9x+3x+4)=(6x+4)(12x+4)