Question

"Dave and Jane wells have a new rectanular driveway. The perimeter of the driveway is 168 feet. The length is 12 feet longer than three times the width. What are the dimensions of the driveway?"

Answer 1

thats easy ,

Answer 2

How would you set it up?

Answer 3

let x be width, y be length

Answer 4

Perimeter = 2x + 2y = 168 , one eqn

Answer 5

but we also know that y=3x+12

Answer 6

2eqns , 2 unknowns

easy to solve

Answer 7

so divide the first by 2

x + y = 84 --- eqn 1

y=3x+12 --eqn2

Answer 8

sub 2 into 1

4x + 12 = 84
4x = 72
x= 18

sub that value into eqn 2

y= 3(18) + 12 = 54 +12 = 66

Answer 9

width=18ft, length = 66ft

Answer 10

thank you so much