Hi there!
We can solve for x by using an elimination of variables.
2x + 5y = 20
-2x + 10y = 25
Add the two equations to eliminate x:
0x + 15y = 45
15y = 45
y = 3
Substitute this value of y into an equation to solve for x:
2x + 5(3) = 20
2x + 15 = 20
2x = 5
x = 2.5