Question

Efectuati produsele :
1. a) (x-1) (x-2)
b) (x-3) (x+6)
c) (x+4) (x+5)
d) (2x+7) (x-2)
e) (1-2x) (3x+5)

Answer 1

1.
a) (x-1) (x-2)=x²-x-2x+2=x²-3x+2
b) (x-3) (x+6)=x²-3x+6x-18=x²+3x-18
c) (x+4) (x+5)=x²+4x+5x+20=x²+9x+20
d) (2x+7) (x-2)=2x²+7x-4x-14=2x²+3x-14
e) (1-2x) (3x+5)=3x-6x²+5-10x=-6x²-7x+5


f) (2x+3)(5x-4)=10x²+15x-8x-12=10x²+7x-12
g) (2a+3b)(3a-b)=6a²+9ab-2ab-3b²=6a²+7ab-3b²
h) (4x+ 3y)(4x-3y)=16x²-9y²

2. (2x-3)(3x+2) + (2x-1)(3x-2) - 2x(x-3)=6x²-9x+4x-6+6x²-3x-4x+2-2x²+6x=
=10x²-6x-4=

(x-4)(2x+7) - (3x+2)(4x+3) + (3-2x)(x+4)=
=2x²-8x+7x-28-12x²-8x-9x-6+3x-2x²+12-8x=
=-12x²-23x-22