Infinity Learning

Lesson 1 — What is an Equation?

An equation is a statement that two algebraic expressions are equal. A linear equation in one variable can be written as ax + b = 0 with a ≠ 0. Example: 5x − 30 = 0.

Solution to an equation

A solution is a value of the variable that makes the equation true.

For 5x − 30 = 0, the solution is x = 6 because substituting gives:

5*(6) − 30 = 30 − 30 = 0

Equality means “same on both sides”

Add/Subtract the same number Multiply/Divide by the same nonzero number

We’ll use these rules later. Today: check a solution by substitution and watch the scale!

Solution Checker (sandbox)

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Left side value
Balance meter
Move the slider to try values!

Try it — Is this a solution?

Question 1 of 5

Is a = −12 a solution to −10a + 5 = 25?

More practice (unlocks as you answer correctly)
← Unit 2