Back to Pre-Algebra
Module_08 // The Finale

SOLVING FOR X

This is it. The culmination of Pre-Algebra. We are taking the grammar of PEMDAS, the physics of number properties, and using them to hunt down the true value of unknown variables.

The Golden Rule

An equation is a perfectly balanced scale. To solve for X, you have to peel away numbers using Inverse Operations. But whatever you do to one side, you MUST do to the exact same thing to the other side.

If you see (+)
Subtract (-)
If you see (-)
Add (+)
If you see (×)
Divide (÷)
If you see (÷)
Multiply (×)

Working Backwards

When simplifying an expression, we use PEMDAS. But when solving an equation, we are unwrapping a present. We work backwards (SADMEP)! Clear your loose addition and subtraction constants before dividing away the coefficient attached to your variable.

Interactive Lab

Logic Router

Current State
2(x + 3) - 4 = 10
What is the best first step?

The Ultimate Cheat Code

Unlike History or English, in Algebra, you can always know if you got the right answer before you turn the test in. Just take your answer and plug it back into the original equation!

2(x) = 82(4) = 8TRUE

Verification Protocol

Knowledge Check: Logic & Strategy1 / 3

To solve the equation "4x - 5 = 15", what should be your VERY FIRST step?

Pre-Algebra Complete!

You are ready to graduate into true algebraic abstraction.

Start: Elementary Algebra