The values x and y are determined when we use the substitution method.
y = x + 5
Apply eh value of y into the equation to solve for x.
3x + y = 25
3x + x + 5 = 25
Combine like terms
3x + x = 4x
4x + 5 = 25
-5 -5 4x = 20
4x/4 = 20/4
x = 20/4
x= 5
Now we know the value of x, and we need to solve for y.
y = x + 5
y = 5 + 5
y = 10
10 = 10
Now we know both of these values.
Answer:
x = 5
y = 10