Exercise 40 Page 238

To find how long it would take for Angel to pick 2 12 cups of blue berries we will use a proportion. We know that she picks blueberries at a constant rate, which will help us to compare the time needed to pick 16 cup of berries with the time needed to pick 2 12 cups of berries. &16 cup/time needed=2 12 cups/time neededWe know she picks 16 cup of blueberries in 2 minutes. Let's call the time needed to pick 2 12 cups x and form our proportion. &16 cup/2 minutes=2 12 cups/x Now that the proportion is written, we will solve it using cross products and then isolating x.

16/2=2 12/x

CrossMult

Cross multiply

1/6 * x = 2 * 2 12

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Write mixed number as a fraction

MixedToFrac

a bc=a* c+b/c

1/6 * x = 2 * 2 * 2 +1/2

Multiply

Multiply

1/6 * x = 2 * 4 +1/2

AddTerms

Add terms

1/6 * x = 2 * 5/2

DenomMultFracToNumber

2 * a/2= a

1/6 * x = 5

MoveRightFacToNumOne

1/b* a = a/b

x/6 = 5

MultEqn

LHS * 6=RHS* 6

x = 30

Angel needs 30 minutes to pick the berries.