Question

x^2 - 10x- 3 =0 to the nearest tenth

Answer 1

Given:

$x^2-10x-3=0$

Find the solution.

Sol:

Use quadratic formula then,

$\begin{gathered} ax^2+bx+c=0 \\ \\ x=\frac{-b\pm\sqrt{b^2-4ac}}{2a} \end{gathered}$

Apply the formula is:

$\begin{gathered} x^2-10x-3=0 \\ \\ x=\frac{-(-10)\pm\sqrt{(-10)^2-4(1)(-3)}}{2(1)} \\ \\ x=\frac{10\pm\sqrt{100+12}}{2} \\ \\ x=\frac{10\pm\sqrt{112}}{2} \end{gathered}$

So the value of x is:

$\begin{gathered} x=\frac{10\pm\sqrt{112}}{2} \\ \\ x=\frac{10\pm\sqrt{28\times4}}{2} \\ \\ x=\frac{2(5\pm\sqrt{28})}{2} \\ \\ x=5\pm\sqrt{28} \\ \\ x=5\pm5.29 \\ \\ x=0.29,x=10.29 \end{gathered}$

So the value of "x" is 0.3 and 10.3