Question

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....
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Answer 1

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

Answer 2

l = (21/2)m

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!