Find the values of a and b for which the following pair of equations have infinitely many solutions:-
1.2x+3y=7 and (a-b)x + (a+b)y=3a+b-2
2.2x-(2a+5)y=5 and (2b+1)x-9y=15
Find the values of a and b for which the following pair of equations have infinitely many solutions:-
1.2x+3y=7 and (a-b)x + (a+b)y=3a+b-2
2.2x-(2a+5)y=5 and (2b+1)x-9y=15