2.2 Algebra Mental Math and Equations (p.38-39)

I. Equation: is a statement showing that two quantities are equal (all equations have an equal sign). Examples:
6+7=13
k-3=1
a+b=11

II. Solution: find the solution is finding the value of a variable (a letter or symbol representing a number) in an equation. For example in the following equation:
16=c+9
The solution is c=7

Watch this Explanation of Equations from Harcourt math.