How do you solve #2x + y = -1# and #x - 2y = 7#?
1 Answer
Aug 17, 2015
x = 1 ; y = - 3
Explanation:
2x + y= −1 ___(1)
x − 2y = 7 ____(2)
2x - 4y = 14 ------------------------(3)
Subtract (3) from (1)
2x + y= −1
2x - 4y = 14
5y = - 15
y = -3
Substitute y = - 3 in equation (1)
2x + ( - 3) = - 1
2x - 3 = - 1 Multiply both sides by 5
10x - 15 = - 5
10x = - 5 + 15 = 10
x =
x = 1
