Warmup Problems for 11/2

Answers for page 120 #8-15, 22-23

3.5: Solving Proportions

Solving Proportions

• Some proportions are easy to solve mentally. We use what we know about equivalent fractions to solve them. For example:

Solving Proportions

• Other proportions are not easy to solve mentally. For example:

How to Solve Proportions using the Multiplication Property of Equality

• We can use the MPoE to solve any proportion. For example:

• Starting with this equation:

• Multiply both sides by 8.4 and x:

• Simplify:

• Simplify again:

• Solve by dividing:

We need a shortcut!

• When we solved

Which two numbers did we end up multiplying?

Which number did we divide by?

What’s the shortcut?