Question

asked Dec 15, 2017 29.5k views

2 Answers

EFreak · Answer 1 · 2017-12-16T15:33:10+0000

Let x sq. ft be the area Melinda shovels per minute and y sq. ft be the area Paul shovels per minute.

1. Together they shoveled 450 square feet of sidewalk in 30 minutes, then

30x+30y=450.

2. Melinda shoveled for 20 minutes while Paul shoveled for 25 minutes to complete 345 square feet of driveway. Then

20x+25y=345.

3. Solve the system of equations:

$\left\{\begin{array}{l}30x+30y=450\\20x+25y=345.\end{array}\right.$

Divide the first equation by 30 and the second one by 5:

$\left\{\begin{array}{l}x+y=15\\4x+5y=69.\end{array}\right.$

From the first equation
x=15-y and

$4(15-y)+5y=69,\\ \\60-4y+5y=69,\\ \\y=9\ ft^2.$

Then
$x=15-9=6\ ft^2.$

Paul can shovel
$9-6=3\ ft^2$ more than Melinda can.

Dastin · Answer 2 · 2017-12-21T23:16:22+0000

Answer:

Paul can shovel 3 square feet more than Melinda in one minute.

Explanation:

Let Melinda shovels driveways in x square feet in one minute and Paul shovels y square feet in one minute.

From first statement of the question.

Together they shoveled 450 square feet in 30 minutes.

Then equation will be 30x + 30y = 450

We solve it further dividing by 30 on each side of the equation.

x + y = 15 -------(1)

Second statement says Melinda shoveled for 20 minutes and Paul shoveled for 25 minutes to complete 345 sq. feet.

The equation will be 20x + 25y = 345

Further we divide the equation by 5

4x + 5y = 69--------(2)

Now we multiply equation 1 by 4 and subtract it from equation 2.

(4x + 5y) - (4x + 4y) = 69 - 60

y = 9

by putting the value of y in equation number 1.

x + 9 = 15

x = 15 - 9 = 6

Now we have to find the difference between per minute shovel done by Paul and Melinda.

y - x = 9 - 6 = 3

Therefore Paul can shovel 3 square feet more than Melinda.

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