Question

Your class is planning a breakfast bake sale and you have been tasked to bake the donuts and bagels. The system below represents the total amount of flour, in pounds, needed to replicate a batch-of-six bagel recipe and a batch-of-twelve donut recipe. You will be replicating the donut recipe d number of times and the bagel recipe b number of times. 3d + 5b = 21 d + b = 5

Answer 1

3 bagel recipe and 2 doughnut recipes are needed

Explanation:

Given the expression

3d + 5b = 21 .. 1

d + b = 5 .... 2

We can use the expression to look for the amount of doughnut recipe and bagel recipe needed by solving the equations simultaneously

Multiply equation 1 by 1 and 2 by 3 to have;

3d + 5b = 21 .. 3

3d + 3b = 15 .... 4

Subtract 3 from 4

5b - 3b = 21 - 15

2b = 6

b = 6/2

b = 3

Substitute b = 3 into equation 2;

From 2,

d = b = 5

d + 3 = 5

d = 5 - 3

d = 2

Hence 3 bagel recipe and 2 doughnut recipes are needed