How do you solve the system of equations #4x + y = 1# and #x+y=4#?

1 Answer
May 1, 2016

x=-1
y=5

Explanation:

4x +y =1
x + y = 4
if you subtract those, you get 3x=-3, x=-1
if x=-1, y=5 (in elimination method)

if you would like to solve it as substitution method,
x+y=4 --> y=4-x
so 4x+y=1
is
4x+4-x=1
----> 3x=-3
x=-1
y=5