Question

Which of the following is a solution for the system y = -3x + 5 and y = 2x + 5?
A. (1, 7)
B. (5, 0)
C. (2, -1)
D. (0, 5)

Answer 1

lets sub y = -3x + 5 into the second equation y = 2x + 5
-3x + 5 = 2x + 5
bring -3x over to the right and the positive five to the left.
0 = 5x
x = 0
sub x = 0 into the first or second equation, lets use the second one.
y = 2(0) + 5
y = 0 + 5
y = 5

so now we have x = 0 and y = 5 so the solution is (0,5)