Out of a group of swans, $\frac{7}{2}$ times the square root of the total number are playing on the share of a pond. The two remaining ones are swinging in water. Find the total number of swans.
Out of a group of swans, $\frac{7}{2}$ times the square root of the total number are playing on the share of a pond. The two remaining ones are swinging in water.
To do:
We have to find the total number of swans.
Solution:
Let the total number of swans be $x$.
This implies,
Number of swans playing on the share of a pond$=\frac{7}{2}\times \sqrt{x}$
Number of swans swinging in water$=2$.
Therefore,
$x=2+\frac{7}{2}\times \sqrt{x}$
$x-2=\frac{7}{2}\times \sqrt{x}$
$(x-2)^2=(\frac{7}{2}\times \sqrt{x})^2$ (Squaring on both sides)
$x^2-4x+4=\frac{49}{4}x$
$4(x^2-4x+4)=49x$
$4x^2-16x+16-49x=0$
$4x^2-65x+16=0$
Solving for $x$ by factorization method, we get,
$4x^2-64x-x+16=0$
$4x(x-16)-1(x-16)=0$
$(4x-1)(x-16)=0$
$4x-1=0$ or $x-16=0$
$4x=1$ or $x=16$
$x=\frac{1}{4}$ or $x=16$
Therefore, the value of $x$ is $16$. ($x$ cannot be a fraction)