Question

Posted by Joseph Georgeabout 2 hours ago

(l+3)(b-4) = lb - 67
lb - 4l + 3b - 12 = lb - 67
-4l + 3b = -55
it can also be written as
4l-3b = 55 ---(1)


(l-1)(b+4) = lb + 89
lb +4l - b +4 = lb +89
4l - b = 85 ---(2)

subtracting 2 from 1

4l - 4l -3b +b = 55 - 85
-2b = -30
b = 15

putting this in 1

4l - 3(15) = 55
4l - 45 = 55
4l = 100
l= 25

lenght = 25 m
bredth = 15 m..see this was the solution sir and i want to ask that (l-1)(b+4) openings means how to open it ..my ans is coming as-4 but here +4.plz clear itttt

Answer 1

A slight correction.

Opening the (l-1)(b+4) gives

=> lb + 4l -b -4 = 89 + lb

4l - b = 93 ...(2)

Subtracting 2 from 1


4l - 4l -3b +b = 55 - 93
-2b = -38
b = 19 cm


Given in (2)

4l - b = 93

=> 4l - 19 = 93

4l = 112
l = 112/4
l = 28 cm



Therefore b = 19cm and l = 28cm