Question

(a-9)²=
(3x-y)²=
(7x+a)²=
(3s+2в )(3a-2в )

Answer 1

Объяснение:

1) (a-9)²= а²-18а+81

2)(3x-y)²= 9х²-6ху+у²

3)(7x+a)²= 48х²+14ах-а²

4) (3а+2в )(3a-2в)= 9а²-4в²

Answer 2

Ответ:

$(a-9)^{2} =a^{2} -2x*9+9^{2} =a^{2} -18a+81\\(3x-y)^{2} =(3x)^{2} -2*3xy+y^{2} =9x^{2} -6xy+y^{2}\\ (7x+a)^{2} =(7x)^{2}+2*7xa+a^{2} =49x^{2} +14ax+a^{2} \\(3s+2в )(3a-2в )=(3s)^{2} -(2b)^{2} =9s^{2} -4y^{2}$