Question

5. At PrintAll copying, a new copying machine can produce five more than twice the number of copies per hour of the old copy machine. If the new machine produces 205 copies per hour, how many copies can the old machine produce? Show the equation you used to determine the answers.

6. A recipe calls for 2 cups of milk for every 6 1/4 cups of flour. If you increase the flour to 43 3/4 cups, how many cups of milk will you use?

Answer 1

Explanation:

5.

xnew = 205 = 2×xold + 5

200 = 2×xold

xold = 100

the old city machine can produce 100 copies per hour.

6.

2 cups of milk relate to 6 1/4 cups of flour.

such recipes represent a direct dependency of one variable on the other. one variable is always the other variable multiplied by a constant factor.

m = cups of milk

f = cups of flour

m = n×f

2 = n×(6 1/4) = n×(6×4 + 1)/4 = n×25/4

8 = 25n

n = 8/25

now, f = 43 3/4 = (43×4 + 3)/4 = 175/4

so,

m = 8/25 × 175/4 = (8×175)/(25×4) = 2×7 = 14

you will need 14 cups of milk.