Question

How do you solve this question algebraically?

y=x+5 if y=3x

Answer 1

substitution.....sub in 3x for y in the other equation

y = x + 5
3x = x + 5
3x - x = 5
2x = 5
x = 5/2

now sub 5/2 in for x in either of the original equations to find y
y = 3x
y = 3(5/2)
y = 15/2

solution is (5/2, 15/2)