Suppose that the length of a rectangle is 3 inches longer ...?

Question

than the width and that the perimeter of the rectangle is 78

a) set up an equation involving only "L", the length of the rectangle.

b) solve this equation algebraically to find the length of the rectangle. Find the width as well.
length _______, width _______

Answer 1

perimeter is 2L+2W=78

L=W+3 or W=L-3


2L+2(L-3)=78

done

2L+2L-6=78
4L=78+6
L=?

for W, since you know what L is already, use W=L-3

Answer 2

hi, i wish i can help. it particularly is my answer. enable: length=L width=W = L - 3 perimeter = seventy 8 inches Ans: Perimeter = 2 (L) + 2 (L - 3) seventy 8 = 2L + 2L - 6 seventy 8 +6= 4 L 80 4=4L L= 21 inches W = L - 3 W = 21 - 3 W = 18 inches solutions: length 21 inches, Width 18 inches

Answer 3

P = 2L + 2W
L = W + 3 so W = L - 3

P = 2L + 2(L - 3) = 2L + 2L - 6 = 4L - 6

The equation is 4L - 6 = 78

4L = 78 + 6
4L = 84
L = 21

W = L - 3 = 18

length is 21 and the width is 18

Answer 4

For (a)

Length = Width + 3
L = W+3
W= L - 3

Perimeter, P
= 2 (L+W)
= 2L + 2W
= 2L + 2(L-3)
= 2L + 2L - 6
= 4L - 6

Therefore, P = 4L - 6


For part (b),

substitute P=78

78 = 4L - 6
84 = 4L
L = 21

W = L - 3
W = 21 - 3
W = 18

Therefore, length is 21 inches, width is 18 inches

Answer 5

(L+L) + [(L+3)+(L+3)] = 78
2L+2L+6 = 78
4L+6 = 78
4L = 72
L = 18
Lenght of the rectangle: 18 + 3 = 21
Proof: 21+21+18+18 = 78

Answer 6

L = length
W = width
P = perimeter
a)
L = 3 + w (I)
P = 2L + 2w = 78 (II)
Substitute:
(I) L = 3 + w
(II) 2(3 + w) + 2w = 78
6 + 2w + 2w = 78
4w = 78 - 6
4w = 72
w = 72 : 4
w = 18 inches

L = 3 + w
L = 3 = 18
L = 21 inches
......

Answer 7

a.) l=3+w
p=78
2l+2w=78

b) w=18
l=21

Answer 8

L=length
L-3= width
P= 2L + 2w
a.) equation =
78 = 2L+ 2 (L-3)
78=4L-6

b.) solve
78=4L-6
84=4L
21=L
21-3=18
18 =w

Answer 9

a)
L + (L - 3) = 39
2L = 42

b)
L = 21--> length = 21 "
B = 18-->breadth = 18"

Answer 10

2L+2(L-3)=78

2L+2L-6=78
4L=84
L=21
W=18