Question

Виконати множення
1. (а-2)(b-5)
2. (x-10)(x-9)
3. (3y+1)(4y-6)
4. (x-5)(6x2-4x)

Спростити вирази:
1) (х+2)(х+11)-2х(3х-4х)
2) (y-9)(3y-1)-(2y+1)(5y-7)
3) (3х-4)(2х+3)- (х+2)(х+5

Answer 1

Объяснение:

1.

$(a - 2)(b - 5) = ab - 5a - 2b + 10$

2.

$(x - 10)(x - 9) = {x}^{2} - 9x - 10x + 90 = {x}^{2} - 19x + 90$

3.

$(3y + 1)(4y - 6) = 12 {y}^{2} - 18y + 4y - 6 = 12 {y}^{2} - 14y - 6$

4.

$(x - 5)(6 {x}^{2} - 4x) = 6 {x}^{3} - 4{x}^{2} - 30 {x}^{2} + 20x = 6 {x}^{3} - 34 {x}^{2} + 20x$

1)

$(x + 2)(x + 11) - 2x(3x - 4x) = {x}^{2} + 11x + 2x + 22 - 2x \times ( - x) = {x}^{2} + 11x + 2x + 22 + 2 {x}^{2} = 3 {x}^{2} + 13x + 22$

2)

$(y - 9)(3y - 1) - (2y + 1)(5y - 7) = 3 {y}^{2} - y - 27y + 9 - 10 {y}^{2} + 14y - 5y + 7 = - 7 {y}^{2} - 19y + 16$

3)

$(3x - 4)(2x + 3) - (x + 2)(x + 5) = 6 {x}^{2} + 9x - 8x - 12 - {x}^{2} - 5x - 2x - 10 = 5 {x}^{2} - 6x - 22$