Answer: (x,y) = (6,-3)This means 6 goes in the first blank and -3 goes in the second blank.=========================================================Explanation:Solve the second equation for x
x+8y = -18
x = -18-8y
We'll plug that into the first equation and isolate y. This is where substitution comes in. 5x + 7y = 9
5( x ) + 7y = 9
5( -18-8y ) + 7y = 9 ... replace x with -18-8y
-90-40y + 7y = 9
-90-33y = 9
-33y = 9+90
-33y = 99
y = 99/(-33)
y = -3
Use this y value to find x
x = -18-8y
x = -18-8(-3)
x = -18+24
x = 6
The solution is (x,y) = (6,-3)
----------------------Checking the answer:Let's check the first equation5x+7y = 95(6)+7(-3) = 9 ... plug in (x,y) = (6,-3)30-21 = 99 = 9 .... true equationDo the same for the second equation as wellx+8y = -186 + 8(-3) = -186 - 24 = -18-18 = -18 .... also trueBoth equations are true when we plug in (x,y) = (6,-3), so the solution is confirmed.