Question

Descompuneti in factori:
a) 16(2x-7)la patrat-9(x-3)la patrat
b)xla puterea a 3 a-9xla patrat-9x+81
c)xlapatrat-5x-24

Answer 1

a)16(2x-7)^2-9(x-3)^2=
[4(2x-7)-3(x-3)]•[4(2x-6)+3(x+3)]=
(8x-28-3x+9)•(8x-27+3x-9)=
(5x-19)•(11x-37)

b)x^3-9x^2-9x+81
x^2•(x-9)-9(x-9)=
(x^2-9)•(x-9)=
(x-3)•(x+3)•(x-9)

c)x^2-5x-24=
x^2+3x-8x-24=
x•(x+3)-8(x+3)=
(x-8)•(x+3)

^inseamna la puterea
•inmultire