Question

The length of a hall is $5m$ more than its breadth. If the area of the floor of the hall is $84m^2$, what is the breadth of the hall?

Answer 1

Let the breadth of the hall be $x$.

The length will be $(x+5)$.

The area of the hall is $84m^2$.

$\therefore x(x+5)=84$

$\Rightarrow x^2+5x-84=0$

$\Rightarrow x^2+12x-7x-84=0$

$\Rightarrow x(x+12)-7(x+12)=0$

$\Rightarrow (x-7)(x+12)=0$

$\Rightarrow x=7$ or $x=-12$

As length cannot be negative, $x=7$.