Question

Find values of x and y for this equation x-y=8,
3x-3y=16
​

Answer 1

x - y = 8 ---------------------(1)
3x - 3y = 16 ----------------(2)

mutiplying equation 1 by 2
2x - 2y = 16 ---------------(3)

subtracting equation 3 from equation 1
_3x - 3y =16
2x - 2y =16
------------------
x - y = 0 ------------------------(4)
adding equation 1 and equation 4
x - y = 8
+
x - y =0
----------------
2x = 8
x = 8/2
x =4

put x =4 in equation no.4
x - y = 0
4 - y =0
-y = -4
y =4

( x,y) = (4,4) is the soln