home solving equations with fractions methods for solving quadratic equations solving equations solving equations linear equations solving equations solving equations with variables on each side solving equations linear equations solving linear equations steps for solving linear equations solving equations with variables on each side solving quadratic equations solving equations solving equations steps for solving linear equations quadratic equations writing linear equations solving equations solving rational equations solving equations solving equations solving systems of equations using elimination solving linear equations solving equations solving quadratic equations methods for solving quadratic equations solving equations solving equations equation solving resources
Try the Free Math Solver or Scroll down to Tutorials!

 Depdendent Variable

 Number of equations to solve: 23456789
 Equ. #1:
 Equ. #2:

 Equ. #3:

 Equ. #4:

 Equ. #5:

 Equ. #6:

 Equ. #7:

 Equ. #8:

 Equ. #9:

 Solve for:

 Dependent Variable

 Number of inequalities to solve: 23456789
 Ineq. #1:
 Ineq. #2:

 Ineq. #3:

 Ineq. #4:

 Ineq. #5:

 Ineq. #6:

 Ineq. #7:

 Ineq. #8:

 Ineq. #9:

 Solve for:

 Please use this form if you would like to have this math solver on your website, free of charge. Name: Email: Your Website: Msg:

Using Multiplication and Division

After studying this lesson, you will be able to:

• Solve equations using multiplication and division.

Review of Steps for Solving Equations:

1. Remove parentheses by multiplying (this step is not always necessary)

2. Collect like terms on each side of the equal sign

3. Isolate the variable by undoing the operation

4. Check by substituting the solution into the original equation

Example 1

 This equation can be solved by cross multiplying. 56 = 7a Use cross multiplication to create a new equation. (4 times 14 and 7 times a) To isolate the variable we have to "undo" the 7 times a. The opposite of multiplication is division, so we divide each side by 7 8 = a 56 divided by 7 is 8 and 7a divided by 7 is a

Example 2

 First, let's convert the mixed numbers to improper fractions Since we have multiplied by y, we need to "undo" by dividing Remember, dividing by a fraction is done by multiplying by the reciproc Multiply each side by and cancel out; cross cancel -81 and -27 and 20 and 5

Check:

substitute for 4 y 4 in the equation where we converted to improper fractions

Example 3

 10p = -100 Since 10 is multiplied by p, we need to "undo" the operation by dividing by 10 Both sides are divided by 10 p = -10

Check by substituting -10 in the original equation

10 (-10) = -100

-100 = -100