Answers

2014-12-01T19:43:11+05:30
A.T.Q
When x = 3 and y = 5
3a + 5b = 7 ----------------------------(1) 

When x =1 and y = 4
a + 4b = 7
a = 7 - 4b ------------------(2) 

Putting the value of a  in (1)

3(7 - 4b) + 5b = 7
21 - 12b + 5b = 7
- 7b = 7 - 21
- 7b = -14
b = -14/-7
b = 2

Now for a , putting the value of b in 2 
a = 7 - 4b 
a = 7 - 8
a = - 1 
2 4 2