Question

please help this is my first post

The perimeter of a rectangle is 50 cm and the length is 4 cm longer than the width. Write and solve the system of equations using the substitution method.

A. width = 10 cm, length= 14 cm
B. width = 10 1/2 cm, length= 14 1/2 cm
C. width = 11 cm, length= 15 cm
D. width = 23 cm, length= 27 cm

Answer 1

let

W = width
L = length

perimeter = 2(L+W)
L = W + 4

do you think you can take it from here?

Answer 2

no i dont understand any of this lol thats why im a senior retaking algebra one

Answer 3

well, to find the perimeter of a rectangle, we add the width and length, then multiply everything by 2, so

perimeter = 2(L+W)

make sense so far?

Answer 4

yes that makes sense

Answer 5

ok, the problem also tells us that

"length is 4 more than the width"

so L = W + 4, make sense so far?

Answer 6

yes

Answer 7

great, now let's put them together and go from there

perimeter = 50 = 2(L+W)
L = W + 4

now, the second equation tells us that we can replace "L" with "W+4" whenever we see L, so we can plug that into the first equation, giving us:

50 = 2(L+W) = 2(W + 4 + W)

with me so far?

Answer 8

kinda

Answer 9

well, the second equation tells us that "length" is the same as "width+4" so we can replace "length" with "width + 4". the reason why we do this is to make all the letters in the first equation the same, so we can find width

50 = 2(W + 4 + W)

we can put W + W together to get 2W, which gives us

5= 2(2W+4), with me so far?

Answer 10

yes im with you

Answer 11

ok, so we have

50 = 2(2W+4)

we can divide both sides by 2 to get

25 = (2W+4)

do you think you can solve for W now?

Answer 12

i think i got it

Answer 13

ok, give it a shot and tell me what W is

I'll guide you if you get stuck

Answer 14

ok i have no idea

Answer 15

no worries

25 = (2W+4)

subtract 4 from each side, what do you get?

Answer 16

wait is the answer D

Answer 17

nope, not D, please try the problem with me

25 = (2W+4)

subtract 4 from both sides of the equals sign

Answer 18

subtract 4 from 25 thats 21 ok

Answer 19

its B

Answer 20

what about the right side?

2W + 4 - 4 = ?

Answer 21

its B :)

Answer 22

great

Answer 23

thank you!!!!!!!!