Solving One Step Equations Lesson Plan

An Equation is a mathematical sentence with an equal sign.

A Variable is a letter representing a number.

x = 3

2 + x = 2 + 3 = 5

x = 8

2x 4 = 4

16 4 = 4

To solve one-step equations use the inverse operation.
Addition is the inverse of subtraction and vice versa.
Multiplication is the inverse of division and vice versa.

Variables are used when the equation ( or mathematical sentence) stays the same,
but the numbers (or values) change.

Click HERE to practice.

Once you have solved an equation, use a formal check to make sure your solution is correct.

Example: x + 4 = -12
The inverse operation is subtraction of 4 from both sides.
x + 4 – 4 = (-12) – 4
x = -16
?
Check:(-16) + 4 = -12
-12 = -12

Example: d – 8 = -15
The inverse operation is addition of 8 to both sides.
d – 8 + 8 = -15 + 8
d = -7
?
Check: (-7) – 8 = -15
-15 = -15

Example: -4c = 44
The inverse operation is division of each side by -4.
-4c (-4) = 44(-4)
c = -11
?
Check: (-4) x (-11) = 44
44 = 44

Example: F8 = -4
The inverse operation is multiplication of each side by 8.
8 x f8 = (-4) x 8
f = -32
?
Check: (-32)8 = -4
-4 = -4

Example: Jack Nickles is behind in a golf

tournament. He currently is at – 1 stroke. The leader John Weekly is at – 8 strokes. What score does Jack need on the last hole to win the tournament?
Write an equation to represent this problem and then solve it.

ANSWER: j + (-1) = -8
The inverse operation is
subtraction of – 1 from
both sides.

j + (-1) – (-1) = (-8) – (-1)
j = -7
?
Check: (-7) + (-1) = -8
-8 = -8