-10x + 5y = 15
Divide everything by 5.
-10x/5 + 5y/5 = 15/5
-2x + y = 3
So, we can imagine some values to this equality
If x = -1 and y = 1 we have
-2.(-1) + 1 = 3
2 + 1 = 3
3 = 3
Another way we can say:
-10x + 5y = 15
5y = 10x + 15
Divide everything by 5.
y = 2x + 3
So just imagine values to x, let's make 0, 1 and 2.
y = 2.0 + 3
y = 0 + 3
y = 3
y = 2.1 + 3
y = 2 + 3
y = 5
y = 2.2 + 3
y = 4 + 3
y = 7
So, when x = 0, y = 3.
When x = 1, y = 5.
When x = 2, y = 7.
