Answer:
x = 7 and y = −2
(7, -2)
Step-by-step explanation:
x = 1 - 3y
3x + 3y = 15
Substitute −3y + 1 for x in 3x + 3y = 15:
3(1 - 3y) + 3y = 15
3 - 9y + 3y = 15
3 - 6y = 15
-3 -3
-6y = 12
/-6 /-6
y = -2
Now we solve for x. Substitute −2 for y in x = −3y + 1:
x = 1 - 3y
x = 1 + (-3)(-2)
x = 1 + 6
x = 7
Now we check our solution.
x = 1 - 3y
7 = 1 + (-3)(-2)
7 = 7 ✅
3x + 3y = 15
3(7) + 3(-2) = 15
21 - 6 = 15
15 = 15 ✅
