How do you find the solution of the system of equations #x+3y=12# and #x-y=4#?
1 Answer
May 13, 2015
x + 3y = 12 (1)
x - y = 4 (2)
(1) gives x = 12 - 3y. Replace x by (12 - 3y) into (2):
12 - 3y - y = 4 -> -4y = -8 -> y = 2
x = 12 - 3(2) = 6
Check:
(1): 6 + 6 = 12. Correct
(2) : 6 - 3 = 4. Correct