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let the length and breadth of rectangle be x and y.
According the first condition :-
A = l × b = xy ✅ ....Area of rectangle
l = (x + 3), b = (y - 4) and A = xy - 67
•°• (x + 3) × (y - 4) = xy - 67
x(y - 4) + 3(y - 4) = xy - 67
xy - 4x + 3y - 12 = xy - 67
-4x + 3y = -67 + 12
4x - 3y = 67 - 12
4x - 3y = 55 ...........(a)
According to the second Condition:-
l = (x - 1), b = (y + 4) and A = xy + 89
(x - 1) × (y + 4) = xy + 89
x(y + 4) - 1(y + 4) = xy + 89
xy + 4x - y - 4 = xy + 89
4x - y = 89 + 4
4x - y = 93 .........(b)
solving equation a and b:-
subtracting equation a from b
4x - y = 93
-(4x - 3y = 55)
2y = 38
y = 38/2
y = 19
substituting y = 19 in equation a:-
4x - 3×19 = 55
4x - 57 = 55
4x = 55 + 57
4x = 112
x = 28
Dimension
length = 28 , breadth = 19
let the length and breadth of rectangle be x and y.
According the first situation :-
A = l × b = xy ....Area of rectangle
l = (x + 3), b = (y - 4) and A = xy - 67
now,
•°• (x + 3) × (y - 4) = xy - 67
x(y - 4) + 3(y - 4) = xy - 67
➬xy - 4x + 3y - 12 = xy - 67
➬-4x + 3y = -67 + 12
➬4x - 3y = 67 - 12
➬4x - 3y = 55 ...........(eq 1)
According to the second situation:-
l = (x - 1), b = (y + 4) and A = xy + 89
now,
(x - 1) × (y + 4) = xy + 89
➬x(y + 4) - 1(y + 4) = xy + 89
➬xy + 4x - y - 4 = xy + 89
➬4x - y = 89 + 4
➬4x - y = 93 .........(eq 2)
solving equation a and b:-
subtracting equation 1 from 2
4x - y = 93
➬-(4x - 3y = 55)
➬2y = 38
➬y = 38/2
➬y = 19
substituting y = 19 in equation 1:-
4x - 3×19 = 55
➬4x - 57 = 55
➬4x = 55 + 57
➬4x = 112
➬x = 28
So, length = 28 , breadth = 19.