2. (i) For which values of a and b does the following pair of linear equations have an infinite number of solutions? 2x +3y =7 ; (a – b) x +(a +b) y =3a +b –2

2. (i) For which values of a and b does the following pair of linear equations have an infinite number of solutions?

2x +3y =7  ; (a – b) x +(a +b) y =3a +b –2

2x +3y =7

Subtract 7 both side we get

2x + 3y  - 7 =  0

 (a – b) x +(a +b) y =3a +b –2

Subtract 3a + b -2 both side we get

(a – b) x +(a +b) y  - (3a + b – 2) = 0

Compare with

Hence answer is a = 5 and b = 1