Solve this system of equations using substitution (show your work)

Question

x+3=7
3x+y=7

Answer 1

First solve for x in the first equation:
x + 3 = 7
x = 7 - 3
x = 4

Next, substitute x = 4 into the second equation:
3(4) + y = 7
12 + y = 7
y = 7 - 12
y = -5

Therefore, the solution to the system of equations is x = 4 and y = -5.