Question

Ex 7 va rog, dau coroana

Answer 1

Răspuns:

a) 5x²-4x-8

b) -13x-24

c) x³+2x²+4x

d) 7x²+3x

e) x³+4x²-14x-11

f) -13x³+6x²+54x-50

Explicație pas cu pas:

a)

(x-3)(x+2) + (2x+1)(3x-2) - 2x(x+1) =

= x²+2x-3x-6 + 6x²-4x+3x-2-2x²-2x

= 5x²-4x-8

b)

(x-6)(2x+5) - (x+2)(x+3) + (3-x)(x+4) =

=  2x²+5x-12x-30 - x²-3x-2x-6 + 3x+12-x²-4x  

=  -13x-24

c)

(x²+x)(x+1) - x²(2+x) + (x+2)(3+x²) - 6 =

=  x³+x²+x²+x - 2x²-x³ + 3x+x³+6+2x² - 6

=  x³+2x²+4x

d)

(x²+2x)(x+3)+2x(x²-x-1) - (3x-1)(x²-x) =

= x³+3x²+2x²+6x + 2x³-2x²-2x - 3x³+3x²+x²-x

= 7x²+3x

e)

(3x+1)(x²+2x-5) - (x+2)(2x²-x+3) =

= 3x³+6x²-15x+x²+2x-5 - (2x³-x²+3x+4x²-2x+6)

= 3x³+7x²-13x-5 - 2x³-3x²-x-6

=  x³+4x²-14x-11

f)

(x-4)(2x²+x+3) + (3x-2)(x-5x²+19) =

= 2x³+x²+3x-8x²-4x-12 + 3x²-15x³+57x-2x+10x²-38

= -13x³+6x²+54x-50