Algebra 1, 2008

 PAGE: 113 SET: Exercises PROBLEM: 1

Original: 72

New: 36

Since the new amount is greater than the original, this is a percent of increase.

The amount of change = New Amount – Original Amount.

The amount of change = .

Let r be the percentage of increase.

Use the original number, 72 as the base.

The percent proportion is

To solve for r, first find the cross products.

(Multiply: )

(Divide each side by 72)

(Cancel common terms)

(Divide: )

The percentage of decrease by 50%.

The percent of change is a percent of decrease.The percentage of decrease by 50%.

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