Question

(x + 1)(x + 2);
(a + b)(a + b);
(a - 2)(3 - a);
(a - b)(a - b);
(3x + 2y)(3x + 2y).



Можно поэалуйста с обяснением типо:
(x + 1)(x + 2)=x°+2x+x+2= x°+3x+2

°=2
​

Answer 1

Ответ:

$(x + 1)(x + 2) = x(x + 2) + 1(x + 2) = {x}^{2} + 2x + x + 2$

$(a + b)(a + b) = {(a + b)}^{2} = {a}^{2} + 2ab + {b}^{2}$

$(a - 2)(3 - a) = a(3 - a) \times ( - 2(3 - a) = - {a }^{2} + 5a - 6$