Question

(2x-1)(x+3)-2(x²+x+1)​

Answer 1

Răspuns:

a) (x+4)(x-3) - (x-1)(x+6) = - 4x - 6

b) (7x-1)(x-3) - 5(x+2)(x+4) = 2x² - 52x - 37

c) (2x-1)(x+3)-2(x²+x+1)​ = 3x-5

d) (x-3)[2x-3(x-1)] + x(x+5) = 9x - 3

e) (2x-3)[3x-2(x+1)] + x(2x-1) = 4x² - 8x + 6

Explicație pas cu pas:

a)

(x+4)(x-3) - (x-1)(x+6) =

= x² - 3x + 4x - 12 - (x²+6x - x - 6)

= x² + x - 12 - x² - 5x + 6

= - 4x - 6

b)

(7x-1)(x-3) - 5(x+2)(x+4) =

= 7x² - 21x - x + 3 - 5(x² + 4x + 2x + 8)

= 7x² -22x + 3 - 5x² - 30x - 40

= 2x² - 52x - 37

c)

(2x-1)(x+3)-2(x²+x+1)​ =

= 2x² + 6x - x - 3 - 2x² - 2x - 2

= 3x - 5

d)

(x-3)[2x-3(x-1)] + x(x+5) =

= (x-3)(2x-3x+1) + x² + 5x

= (x-3)(-x+1) + x² + 5x

= -x² + x + 3x - 3 + x² + 5x

= 9x - 3

e)

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

= (2x-3)(x-2) + 2x² - x

= 2x² - 7x + 6 + 2x² - x

= 4x² - 8x + 6