Please help in math : lenght of rectangle is width+7m. and width of this rectangle is 1/3 of lenght. find lenght of rectangle.
please help and explain

L=W+7

W=1/3L

we can substitute the width in the first relation with 1/3L

L=1/3L+7

we move1/3L to the left

L-1/3L=7

we multiply by 3 to remove the denominator

3L-L-21

2L=21

L=21/2=10.5cm

l = (21/2)m

Step-by-step explanation:

Let's call the length l and width as w.

l = w+7m

(1/3)l=w (Plug in the w value into the first equation)

l = (1/3)l+7m (Now, isolate the l)

(2/3)l = 7m (Multiply both sides by 3/2)

l = (21/2)m

Hope this helps!

oof

step-by-step explanation:

see explanation

step-by-step explanation:

a

(6r + 7) + (13 + 7r) ( remove brackets and collect like terms )

= 6r + 7 + 13 + 7r

= 13r + 20

b

remove brackets and collect like terms

13 - r - 1 + r

= 12 - r

c

remove brackets and collect like terms

= - 8 - r + 2r - 4

= - 12 + r

d

remove brackets and collect like terms

= 7r - - - 6r

[-   - = - - = - ]

= r -