Question

2x + 3y - 7 =0 ;(a-1) x+(a+2) y =3a find the value of a

Answer 1

by trial method
we put the value of x=8&y=-3
1st eq. balance
16-9-7=0
then (a-1)x+(a+2)y=3a
(a-1)×8+(a+2)×-3=3a
8a-8-3a-6=3a
8a-3a-3a=8+6
2a=14
a=7