for the first set of equations, it’s easier to use substitution because both equations are already equal to y.
5x + 7 = 2x + 10
- 7 - 7
5x = 2x + 3
- 2x = - 2x
3x = 3
/3 /3
x = 1
now that you solved for x, plug 1 into an equation to find y
y = 5(1) + 7
y = 5 + 7
y = 12
so the answer is (1,12)
for the next one, use elimination because there is a positive/negative +-2x pair
y = 2x + 18
9y = -2x + 2
the 2x and the -2x will cancel out. add the other terms
10y = 20
divide both sides by 10
y = 10
now that we have the y term, plug it in to solve for x
10 = 2x + 18
-18 -18
-8 = 2x
-4 = x
the answer is (-4,10)