Question

If 31x + 43y = 117 and 43 + 31y = 105, then value of x – y is:​

Answer 1

Answer:

-12

Step-by-step explanation:

Given 31x + 43y = 117 (eqn: a)

and 43x + 31y = 105 (eqn: b)

After doing (eqn: a) - (eqn: b) we will get:

(31x + 43y) - (43x + 31y) = 117 - 105

=> (31 - 43)x + (43-31)y = 12

=> -12x + 12y = 12

=> -x + y = 12

=> x - y = -12