For overnight math fans -- I learned about the Double Intercept form of the linear equation a few years ago -- popular in Europe and I bet Singapore, but not taught in USA.

1. Draw X and Y axes on graph paper and draw a straight line with a Y intercept and an X intercept. They can be plus or minus, but choose positive integers for ease of demonstration.
2. Write an equation in the following Double Intercept form: X/a + Y/b = 1, where 'a' is the X intercept value and 'b' is the Y intercept value.
3. Multiply EACH TERM first by 'a', and then by 'b'. Make sure the X term is plus. This is now the “Standard” form of a linear equation.
4. Subtract the X term from both sides to eliminate it on the left side.
5. Divide each term by the Y term coefficient. Make sure Y is plus. This is now the “Slope - Intercept” form of a linear equation.
6. Now compare the Y intercept value from this equation and see if it matches the number in the first equation and the graph.
7. Calculate the slope by examining the graph and see if it matches the slope in the third equation. These three equations describe THE SAME LINE and the same relationship between X and Y.