Question

12 Efectuati:
a) (x-6)(2x+5)-(x+2)(x+3)+(3x-x)(x+4)
b) (a+b)(a+3b)+(2a-3b)(a+2b)-(a-b)(3a+b)
c) (x²+x)(x+1)-x²(2+x)+(x+2)(3+x²)-6
14 Efectuati
a) (3x+1)(x²+2x-5)-(x+2)(2x²-x+3)
b) (x-4)(2x²+x+3)+(3x-2)(x-5x²+19)
c) (x²-2x+2)(x²+2x-3)-(2x²+x+5)(x-x²-2)

Answer 1

12)
a) (x-6)(2x+5)-(x+2)(x+3)+(3x-x)(x+4)=
2x^2+5x−12x−30−x^2−5x−6+3x^2+12x−x^2−4x=
3x^2−4x−36

b) (a+b)(a+3b)+(2a-3b)(a+2b)-(a-b)(3a+b)=
a^2+3ab+ab+3b^2+2a^2+4ab−3ab−6b^2−3a^2+2ab+b2=
7ab−2b^2

c) (x²+x)(x+1)-x²(2+x)+(x+2)(3+x²)-6=
x^3+x^2+x^2+x−x^3−2x^2+3x+x^3+6+2x^2−6=
x^3+2x^2+4x

14)
a) (3x+1)(x²+2x-5)-(x+2)(2x²-x+3)=
3x^3+6x^2−15x+x^2+2x−5−2x^3−3x^2−x−6=
x^3+4x^2−14x−11

b) (x-4)(2x²+x+3)+(3x-2)(x-5x²+19)=
2x^3+x^2+3x−8x^2−4x−12+3x^2−15x^3+57x−2x+10x^2−38=
−13x^3+6x^2+54x−50

c) (x²-2x+2)(x²+2x-3)-(2x²+x+5)(x-x²-2)=
x^4+2x^3−3x^2−2x^3−4x^2+6x+2x^2+4x−6+2x^4−x^3+8x^2−3x+10=
3x^4−x^3+3x^2+7x+4