The "cook-book" way:
To get the left side of the equation
1. Swap the coefficients of x and y
2x,3y
2. Change the sign of the coefficient of y
2x,-3y
3. Write them added together with an equal sign after them
2x-3y =
4. Substitute the point, x=4, y=-2
2(4)-3(-2)
8+6
14
5. Put that number on the right side (after the equal sign)
2x-3y = 14
It's like magic! No thinking required. Just memorize how to do it.
Edwin
