Solving Equations

One-Step Equations

Solving One-Step Equations

• Goal Your final answer should be

variable = number x = 7

The Golden Rule of Algebra

• Whatsoever you do to one side of an equation, you must ALWAYS do to the other.(Draw a line through the equal sign to divide the equation

into two sides.)

For example: x + 3 = 5 - 3 - 3 x + 0 = 2 x = 2

Keep it balanced.

Goal

Undoing Operations

• To reach your goal, you must isolate the variable on one side by undoing the operation. To zero out a number (or undo it), you simply do the opposite operation. To undo addition, you subtract. To undo subtraction, you add.

To undo multiplication, you divide. To undo division, you multiply.

Solving One-Step Equations

Problem:

Undo addition with subtraction.

Solving One-Step Equations

Solution

Solving One-Step Equations

• Undo subtraction with addition.

x – 4 = -2 + 4 + 4 x + 0 = 2 x = 2

Don’t forget your integer

rules!

Solving One-Step Equations

• Undo multiplication with division.

3x = 9 3 3 1x = 3 x = 3

The 3’s cancel

Solving One-Step Equations

• Undo division with multiplication.

x = 2 5 5∙x = 2 5 ∙ 5

x = 10

The 5’s cancel

Solving One-Step Equations

Remember, keep it balanced …

Now, have fun solving One-Step Equations!