Question

if the width of rectangle is
10cm less than its length and
its perimeter is 50cm
Find the
width of rectangle​

Answer 1

Answer:

W = 7.5 = 15/2

Step-by-step explanation:

∵  P = 2 ( L + W ) -------> (1)

∵ W = L - 10       -------> (2)

substitute by (2) in (1) :

∴ P = 2 (  L + ( L- 10 ) )

∴ P = 2 (  2L - 10  )

∴ p = 4L - 20

∵ p = 50 cm

∴ 50 = 4L - 20

∴ 50 + 20 = 4L

∴ 70 = 4L

∴ L = 70/4

∴ L = 35/2 = 17.5     -------> (3)

substitute by (3) in (2) :

∴ W = 17.5 - 10

∴ W = 7.5 = 15/2

Answer 2

Answer:

Width of rectangle is 7.5cm

Step-by-step explanation:

let width of rectangle be x

and length of rectangle be y

According to first condition

x= y-10

therefore x-y= -10... equation 1

According to second condition

50=2x +2y.... equation 2

Multiply equation 1 by 2

therefore, 2x-2y = -20... equation 3

Adding equation 2 and 3

2x - 2y = -20

+ 2x + 2y = 50

4x. = 30

x= 30÷4 = 7.5

Therefore width of rectangle is 7.5 cm