Q15 of 244 Page 157

If 12x + 17y = 53 and 17x + 12y = 63 then find the value of (x + y).

We have the given pair of equations are:

12x + 17y = 53 …(i)

17x + 12y = 63 …(ii)

Now, adding (i) and (ii) we get:

29x + 29y = 116

29 (x + y) = 116

(x + y) = 4

∴ The value of (x + y) is 4

If and , find the values of x and y.

If and then find the value of (x + y).

Find the value of k for which the system 3x + 5 = 0, kx + 10y = 0 has a nonzero solution.

Find k for which the system kx – y = 2 and 6x – 2y = 3 has a unique solution.