Question

Solve linear equation y=4-x y=x-4

Answer 1

{ y = 4 - x
   y = x - 4

Subsititute  y = x - 4

[ ( x - 4 )] = 4 - x ]

isolate x for ( x - 4 ) =  4  - x

x = 4

For y  = x - 4

Subsititute  x = 4

y = 4 - 4

y = 0

Solution 

x = 4  and y = 0

hope this helps!