1) {2x+3y=1
{3x+5y=2
2) {2a-3b=7
{3a+4b=2

ответ: 2x+3y=1

2x+3y-1=1-1

2x+3y-1=0

Объяснение:

a6+a8=15

a2*a12=56

a1+5d+a1+7d=15

2a1+12d=15|: 2

a1+6d=7.5

a1=7.5-6d

a2*a12=56

(a1+d)(a1+11d)=56

(7.5-6d+d)(7.5-6d+11d)=56

(7.5-5d)(7.5+5d)=56

7.5^2-(5d)^2=56

56.25-25d^2=56

25d^2=0.25

d^2=0.01

d=0.1

ответ: 0,1

5nm+7n²m-8nm²=nm(5+7n-8m)