For the 1st problem, solve the 2nd equation for x.
x = -1 - y
Now, replace x in the 1st equation with (-1 - y)
2(-1 - y) - 3y = 2
-2 - 2y - 3y = 2
-2 - 5y = 2
-5y = 4
y = -4/5
x = -1 - (-4/5) = -1 + (4/5) = -1/5
The solution is (-1/5, -4/5)
For the 2nd problem, multiply the top equation by 15 and the bottom equation by -12. That gives us:
10x - 12y = 15
-36x +12y = 84
Add the two together, which gives us:
-26x = 99
x = -99/26
Now, put this value of x into either equation to solve for y
3(-99/26) - y = -7
-297/26 - y = -7
-y = -7 + 297/26
-y = 115/26
y = -115/26
The solution to this system is (-99/26, -115/26)
