Question

Stanford University's soccer field has an area of 8800 square yards. Its length is 30 yards longer than its width.
1. Write an expression for each dimension (length and width) of the soccer field.
2.Write an equation and solve for the dimensions of the soccer field.

Answer 1

let length = L
and width = W, with me so far?

Answer 2

yes

Answer 3

"length is 30 yards longer than its width. "

means that L = 30 + W

so length = 30 + W
and width = W, that takes care of #1

Answer 4

for #2, we let length*width = area

so

W(W+30) = 8800

solve for W

Answer 5

Do I distribute the W ?

Answer 6

yes

Answer 7

W^2+30W=8800

Answer 8

good, now subtract 8800 from each side

Answer 9

Is it -8800W^2-8770W?

Answer 10

nope

Answer 11

remember that you cannot combine numbers and variables

Answer 12

W^2+30W-8800=0

Answer 13

So it'll be W^2+30W-8800

Answer 14

yes, now factor

Answer 15

W^2+30W-8800 = ?

Answer 16

can and 10 and 880 work?

Answer 17

nope, think carefully

our two factors must add to 30 and multiply to get 8800

Answer 18

W^2+30W-8800 = (W+110)(W-80), know where to go from here?

Answer 19

Do i solve for W?

Answer 20

yes

Answer 21

W=-110 and W=80

Answer 22

good, now remember that W is width, and width must be positive

so W = 80

Answer 23

now find L

Answer 24

L=110

Answer 25

good! that should b everything

Answer 26

Thank you so much!!