Dictionary for Basic and Intermediate Algebra
A | B | C | D | E|F | G | H | I| J | K | L |M |N | O | P | Q | R | S | T | U | V | W |X |Y |Z | How to use this site
» Basic Skills

Distributive Law
Removing Parenthesis
LCD or LCM
Factoring
Fraction
Evaluation Expression

» Topics in Basic & Intermediate Algebra

Function & Graphs
Inequalities
Word Problems
Geometric Formulas
Metric English Systems

» Topic Illustrated using Power Point

Go to PP Presentations
Links

N e w
» Topics in Calculus

Go to Calculus PP Presentations

SOLVING EQUATIONS WITH ONE VARIABLE

A) Simple Equations

Three steps to solve a simple equation:
1. Move all terms containing the unknow to the left side of the equation.
2.
Collect like terms.
3.
Divide by the coefficient of the unknown to get the answer.

Example 1: Solve  5x - 12 = 3x + 4

Solution: 5x -3x = 4 + 12
2x = 16
x = 8

Answer: x = 8

B) Equation with Fractions

Multiply both member of the equation for the Least Common Multiple among all denominators.

Example: Solve     wpe3.jpg (1272 bytes)

Multiplying by the LCD=30 we get:

C) Equation with Parenthesis

Remove the parenthesis performing the corresponding operations and proceed as in 1).
 

Example: Solve 3 – (2x – 3) = 6 + 3(x + 5)

3 – 2x + 3 = 6 + 3x + 15

-2x –3x = 6 + 15 – 6

-5x = 15

x = -3

  D) With Multiple Parenthesis

Remove parenthesis (using FOIL when applicable). Use auxiliary parenthesis for partial results., finally proceeds as in 3)  

Example: Solve 5 +(2x+1)(x+3) = 3x2 –(x+3)(x+2)

5 + (2x2 + 6x +x +3) = 3x2 –(x2 +2x+3x+6)

5 + 2x2 + 6x +x +3 = 3x2 –x2 -2x-3x-6

2x2 + 7x + 8 = 2x2 -5x-6

7x + 5x = -6-8

12x = -14

x = -7/6

E) Fractional Type

Multiply the equation by the LCD Example: Solve

wpe1.jpg (1977 bytes)

Multiplying by the LCD (x-3)(x+2) , we get

wpe2.jpg (3355 bytes)

It's easy to check that x=4 satisfies the equation.

  F) Equation with Radical

Isolate the radical and then power both members of new equation to eliminate the radical.

Do not forget to check your possible solutions!

Example: Solve: wpe5.jpg (1283 bytes)

Isolating the radical we get:

wpe6.jpg (3468 bytes)

Checking x=5, we get

wpe7.jpg (2621 bytes)

So x=5 is the solution.

 F) Equation with no Solution

Example: Solve wpe8.jpg (1264 bytes)
Isolating the radical we get:


Click here for more examples

Amy/Oscar © 2002

SOLVING EQUATIONS WITH ONE VARIABLE

NVCC Alexandria Campus Math Dictionary