Exercise 28 Page 252

We are told that the number of signers of the Declaration was n. We also know that n is 80% of y. In the previous exercise we found that y equals 70. Recall that the percent equation is an equation in which the part is equal to the product of the corresponding percent and the whole. We can represent a is p percent of wwith the following equation. a= p% * wWe can find what 80% of 70 is by substituting p%= 80100 and w= 70 into the formula and solve for a using the Properties of Equality.

a= p% * w

SubstituteII

p%= 80/100, w= 70

a= 80/100 * 70

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Solve for a

MoveRightFacToNum

a/c* b = a* b/c

a=80* 70/100

Multiply

Multiply

a=5600/100

CalcQuot

Calculate quotient

a= 56

Knowing the value of a, let's look at the completed percent equation. 56= 80% * 70 We found that 56 is 80 % of 70. This means that there were 56 signers of the Declaration of Independence.

Checking Our Answer

Checking Our Answer

We can use a model to check our answer.