Question

plzzz plzzz plzz guys help me its v.v.imp....plzzz solve this questions (class10 math)

Answer 1

4)  Area of rectangle = L × B

    take the actual area of rectangle = A

    case 1 : -

    length = L - 5

breadth = B + 3

case 2 :-

length = L + 5

breadth = B - 5

solution

( L-5 ) × ( B + 3 ) = A - 30

( L + 5 ) × ( B - 5 ) = A - 52

here A = L × B

LB + 3L - 5B - 15 = LB - 30....... Eqn 1

LB - 5L + 5B - 25 = LB - 52.......Eqn 2

in both equation 1 & 2 LB is common in LHS and RHS so we can cancel LB

3L - 5B = -30+15

-5L + 5B = -52+27

3L - 5B = -15....... (a )

-5L + 5B = -27......( b)

by solving this both equation we can cancel -5B &+5B

-2L = -42

L = -42 ÷ -2

L = 21 m

Substitute L = 21 in equation ( a )

3×21-5B = -15

63 - 5B = -15

-5B = -15 -63

-5B = -78

  B = 78÷ 5

  B = 15.6 m