The length of a rectangle is 2 1/2 times its width. the permiter of the rectangle is 84cm. find the dimensions of the rectangle

Step-by-step explanation:

The perimeter is twice the sum of the lengths of adjacent sides. If we let w represent the width, then 2.5w can represent the length. The perimeter (in centimeters) is ...

  P = 2(L +W)

  84 = 2(2.5w +w) . . . . . substitute known values

  84 = 7w . . . . . . . . . . . . simplify

  12 = w . . . . . . . . . . . . . .divide by 7

  L = 2.5w = 2.5×12 = 30

The width is 12 cm; the length is 30 cm.

heyyy

step-by-step explanation:

step by step resolutions

1) n+n+1+n+2=51

3n+3=51

3n=48

n=16

the three numbers are 16, 17 and 18.

2) x+15=4x

3x=15

x=5

radha is now 5 years old

3) the two digits are x and y.

y=3x

(10x+y)+(10y+x)=88

y=3x

11x+11y=88

y=3x

x+y=8

x+3x=8

x=2

the original number can be either 28 or 82.

4) n+(n+2)+(n+4)=48

3n+6=48

3n=42

n=14

the numbers are 14, 16 and 18.

5) y=x+3

10y+x+10x+y=143

y=x+3

11x+11y=143

y=x+3

x+y=13

x+x+3=13

2x=10

x=5

the original number can be 57 or 75.

hope this !