Alarge rectangular shaped swimming pool has a perimeter of 1020 meters and its length is 20 meters more than 6 times its width .find its dimension

Perimeter = 1020 m
let width be = X
let length be = 20 + 6 (X)
perimeter of rectangle = 2 ( length + width )
1020 = 2 ( 20 + 6 X + X )
1020 = 2 ( 20 + 7 X )
1020 = 40 + 14 X
14 X = 1020 - 40
14 X = 980
X = 980 / 14 = 70

width = X = 70 meters
length = 20 + 6X = 20 + 6 ( 70 )
= 20 + 420
= 440 meters

HOPE IT HELPED !!

I'm sure the answer is a