Exercise 31 Page 239

Substitute 3 for c and 9 for d in the expression. When multiplying real numbers, the product will be positive if the signs are the same and it will be negative if the signs are different.

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Practice makes perfect

To evaluate the given expression for c = 3 and d = 9, first, we should substitute these values into the expression.

-cd^2

SubstituteII

c= 3, d= 9

- 3( 9)^2

SplitIntoFactors

Split into factors

-3(9)(9)

When multiplying real numbers, the product will be positive if the signs are the same and it will be negative if the signs are different.

cc Same Sign & Different Signs (+)(+)=(+) & (+)(-)=(-) (-)(-)=(+) & (-)(+)=(-) We will use the Associative Property of Multiplication to multiply the first two numbers first. There is one positive number and one negative, so the product will be negative.

-3(9)

Multiply

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Now we will multiply the remaining two numbers. The result of the first multiplication was negative and the third number is positive, so the final product will be negative.

-27(9)

Multiply

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