How to solve simultaneous equations when y =2andx=4

Answer 1

These two lines are horizontal and vertical lines.
They intersect at (4,2) because you can pick any value of x on the line y=2, so pick x=4.

had you graphed the lines, this wpuld have been obvious.

Or, you could have set up
0x+y = 2
x+0y = 4
And the solution would clearly be (4,2)