How do you solve the following linear system: 4x+3y= -2 , 2x-2y= -8?
1 Answer
Nov 12, 2015
(x , y) = ( -2 , 2 )
Explanation:
Let the given equations be
4x + 3y = -2 ..........(i)
2x - 2y = -8 ...........(ii)
Lets multiply equation (ii) by 2, we get
4x - 4y = -16 ..........(iii)
Subtract equation (iii) from (i)
4x + 3y = -2
4x - 4y = -16
( - ) (+ ) (+)
0 + 7y = 14
y = 14/7 = 2
Substituting value of y in equation (i)
4x + 3 X 2 = -2
or, 4x = -2 -6 = -8
or, x = -8/4 = -2
Hence (x , y) = ( -2 , 2 )
Checking
4 X -2 + 3 X 2 = -2
or, -8 + 6 + -2
or -2 = -2
Hence LHS = RHS
