3xy15 xy12 solve using the substitution methodSolution3xy 1

3x-y=15 x+y=1/2 solve using the substitution method.

Solution

3x-y = 15 (1)
x+y = 1/2   (2)

From the second equation:
x = 1/2 - y (3)

I\'ll substitute (3) in (1):
3(1/2-y) - y = 15
3/2 - 3y - y = 15
-4y = 27/2
y = -27/8

Now replacing in (3):
x = 1/2 + 27/8
x = 31/8

Hope this helps