THE FINAL STEP OFTEN WILL BE TO DIVIDE EACH SIDE BY THE COEFFICIENT...

4. The final step often will be to divide each side by the coefficient, leaving the variable equal to anumber.

C

ROSS

-M

ULTIPLYING

You can solve an equation that sets one fraction equal to another by cross-multiplication. Cross-multiplication involves setting the products of opposite pairs of terms equal.

Example

10

becomes 12x= 6(x) + 6(10)

x

=

x

+

6

12

12x= 6x+ 60−6x −6x

x

=

6

0

6

Thus, x= 10

Checking Equations

To check an equation, substitute the number equal to the variable in the original equation.To check the equation from the previous page, substitute the number 10 for the variable x.

10

0

=

10

+

1

1

2

0

=

2

0

2

Simplify the fraction on the right by dividing the numerator and denominator by 2.0

=

1

Because this statement is true, you know the answer x= 10 is correct.

–

A C T M AT H T E S T P R A C T I C E

–

Special Tips for Checking Equations