Question

The pair of equations 2x - y - 4 = 0 and x + y +1= 0 and has

Answer 1

2x - y - 4 = 0

2x-y=0+4

2x-y=4

2x=4+y

x=(4+y)/2 ---- (i)

x + y +1= 0

(4+y)/2 + y=0-1 (by using i)

(4+y+2y)/2 = -1

(4+3y)= -1×2

3y = -2-4

3y = -6

y = -6/2

y = -3