{x-6y=17 {6x=30 {х=5 {х=5 {х=5
{5x+6y=13, {х-6у=17, {5-6у=17, {-6y=12, {у=-2
Ответ:
1-1
2-1
3-2
4-1
5-3
6--10а+2с
7-4
8(n-4)+(n-3)+(n-2)+(n-1)+n=5n-10
a^3-(a+1)^3+3a^2=a^3-(a^3+3a^2+3a+1+3a^2=a^3-a^3-3a^2-3a-1+3a^2=-(3a+1)