The perimeter of a rectangular cardboard is 500cm and its area is 14400cm^2 . Find the dimensions of the cardboard.

Question

parthkohli · Answer

$\color{Black}{\Rightarrow 2(a +b) = 500 }$

$\color{Black}{\Rightarrow ab = 14400 }$

Solve.

anonymous · Answer

How to solve ? o-o ? Help please

anonymous · Answer

Haha ParthKohli already made it simple for you. 

Oh well.

2(a+b) = 500 
a+b = 250 -(1)

ab= 14400  -(2)

Take eqn. (1), and rearrange it to,
a= 250 - b

Substitute the above into eqn.2

(250-b) b = 14400
250b - b^2 = 14400
b^2 -250b + 14400 = 0

Solve for b.

Once you get b then substitute back to (1) and find a then. VOila answer.

anonymous · Answer

If you want to get b the only way is to use the general equation of quadratic formula??

anonymous · Answer

Or factorization?

anonymous · Answer

Factorization will work, but as you are working in very big numbers it is tricky to find the right ones. Both will work fine.

anonymous · Answer

Okays thanks alot :)