the perimetre of rectangle is 240cm .if length is increased by 10% and breadth is decreased by 20% the perimetre remains same. find the length

Answer 1

2(x+y) = 240
2(1.1x+0.8y) = 240

now solve for x.

Answer 2

2l + 2w = 240
l + w = 120
l = 120-w

new length = 1.1l
new width = .8w
2(1.1l) + 2(.8w) = 240
1.1l + .8w= 120
1.1(120-w) + .8w = 120
11(120-w) + 8w = 1200
1320 - 11w + 8w = 1200
-3w = -120
w = 40
then l = 120-40 =80

state a proper conclusion

Answer 3

can't understand what it is said

Answer 4

Please explain clearly