Simultaneous equations are two linear equations that can be solved using bar models. By remembering that the same letter will always have the same value we can work out the missing values. To solve ...

An algebraic equation contains one or more letters in it. Each letter in the equation is called a variable. A variable can change in value. We guess at different values for each letter until our ...

You have that slide rule in the back of the closet. Maybe it was from your college days. Maybe it was your Dad’s. Honestly.

Learn how to calculate payback and discounted payback in Excel with formulas, SCAN, XMATCH, LET, and SWITCH, plus partial-year and error handling ...