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:
Equality means “same on both sides”
We’ll use these rules later. Today: check a solution by substitution and watch the scale!
Solution Checker (sandbox)
0
Left side value
Balance meter
Try it — Is this a solution?
Is a = −12
a solution to −10a + 5 = 25
?