**Question:**

x = 5 and y = 2 is a solution of the linear equation

(a) x + 2y = 7

(b) 5x + 2y = 7

(c) x + y = 7

(d) 5x + y = 7

**Solution:**

(c) (a) Take x + 2y, on putting x=5 and y = 2, we get

5 + 2(2) = 5+ 4 = 9≠7.

So, (5, 2) is not a solution of x + 2y = 7

(b) Take 5x + 2y, on putting x = 5 and y = 2, we get

5x 5 + 2 x2 =25+ 4 = 29≠7

So, (5, 2) is not a solution of 5x + 2y = 7.

(c) Take x + y, on putting x = 5 and y = 2, we get 5+2=7

So, (5,2) is a solution of x + y = 7.

(d) Take 5x + y, on putting x = 5 and y = 2, we get

5×5 + 2=25 + 2 =27 ≠7

So, (5, 2) is not a solution of 5x + y = 7.