Question

What is the positive solution of x2 – 36 = 5x?

Answer 1

hope this will help......

Answer 2

The quadratic equation is given: $x^2-36= 5x$

or we can write this as:

$x^2-5x-36=0$

For a general quadratic equation $ax^2+bx+c =0$, the quadratic formula is given by : $x = \frac{-b\pm\sqrt{b^2-4ac}}{2a}$

From the given equation we have,

a = 1, b = -5 and c = -36

then;

$x = \frac{-b\pm\sqrt{b^2-4ac}}{2a} = \frac{-(-5)\pm\sqrt{(-5)^2-4(1)(-36)}}{2(1)}$

or

$x = \frac{5\pm\sqrt{25+144}}{2} = \frac{5\pm\sqrt{169}}{2}$

or

$x = \frac{5\pm 13}{2}$

or

x = $\frac{5+13}{2}$ and  x =  $\frac{5-13}{2}$

On solving we get;

x= 9 and x = -4

Therefore, the positive solution of the equation $x^2-36= 5x$ is 9.