Question

Solve 2x + 3y = 11 and 2x – 4y = – 24 and hence find the value of ‘m’ for which y = mx + 3.

Answer 1

2x + 3y = 11    (1)

2x – 4y = – 24  (2)

From equation (1), we obtain

`x = (11-3y)/2`

Substituting this value in equation (2), we obtain

`2((11-3y)/2) - 4y = -24`

11 - 3y-4y = -24

-7y = - 35

y = 5   (4)

Putting this value in equation (3), we obtain

`x = (11-3xx5)/2 = -4/2 = -2`

Hence x = -2, y = 5

Also

y = mx+3

5 = -2m + 3

-2m=2

m = -1