Question

If 7x+6y=40 and 6x+7y=38 , then what is the value of (x-y)​

Answer 1

multiplying eq1 by 6 and eq2 by 7

so 42x+36y = 240

42x+49y = 266

- - -

-----------------------------

0 - 13y = -26

y = 2

and 7x+6×2 = 40

x = 4

so,, x-y = 4-2 = 2 ...ans.