Plz solve dis pair of equation

Given set:

ax+by=c  ..(1)

bx+ay=1+c  ..(2)

Adding (1) and (2),

x+y=1/(a+b) (2c+1)  ...(3)

Subtracting (1) from (2),

x-y=1/(b-a) ...(4)

adding 3 and 4,

x=1/2((2c+1)/(a+b)+(1/b-a))

Subtracting (3) and (4)

y=1/2((2c+1)/(a+b))-(1/(b-a)))