Question

Даю 20 баллов б, помогите!!!!!!!!!!!!!!

Answer 1

Ответ:

(m-5)^2= m^2-10m+25

(2a+7b)^2= 4a^2+28ab+49b^2

x^2-81= (x-9)(x+9)

y^2-6y+9= (y-3)^2

(a+3)(a-3)= a^2-9

(8x+5y)(5y-8)=25y^2-64x^2

16x^2-49= (4x-7)(4x+7)

x+5y=15

2x-y=8

x=15-5y

2(15-5y)-y=8

30-10y-y=8

-11y=-22

y=2 x=5

4x-7y=1

2x+7y=11

x=(1+7y)/4

2((1+7y)/4) +7y=11

(1+7y)/2 +7y=11

1+7y+14y=22

21y=21

y=1

x=2