Guys can you help me on this question please I am so confused!!!!!

Question

The perimeter of a wooden rectangular deck is 90 feet. The length is 5 feet less than 4 times the width. What is the length and the width of the deck?

Answer 1

For this we have to turn the question into a formula so that we can solve the problem.

The perimeter is twice the l = length and also twice the w = width so we get the equation 90 = 2l + 2w

Now for the second equation you have to think about the relationship between the variables.

This is saying to get the length, we have to multiply the width by 4 and then subtract 5.

With this we get l = 4w - 5

Now we have to substitute the variables into the other equation (For this we will substitute the second equation (l = 4w - 5) into the first (90 = 2l + 2w))

90 = 2(4w - 5) + 2w

90 = 8w - 10 + 2w

100 = 10w

10 = w

Now we have to solve for the other variable l and you can use either equation, but let us use the second

l = 4 (10) - 5

l = 40 - 5

l = 35

∴ l = 35, w = 10

Answer 2

Hi Siri

Perimeter = 90

Perimeter = 2* (Length + Width)

Translating the words into equation:

Length = 4* Width -5

Thus, pluggling in this Length expression: Perimeter = 8* Width -10 + 2* Width = 10* Width - 10

Thus 90 = 10* Width - 10

Then, Width = 10 and thus Length = 4* Width -5 = 35