Question

Solve the quadratic equation x^2 3x = 40 using the quadratic formula

Answer 1

We have the equation:

`x^2+3x=40`

We have to find its roots with the quadratic formula:

`\begin{gathered} x^2+3x-40=0 \\ x=(-3)/(2\cdot1)\pm\frac{\sqrt[]{3^2-4\cdot1\cdot(-40)}}{2\cdot1} \\ x=-(3)/(2)\pm\frac{\sqrt[]{9+160}}{2} \\ x=-(3)/(2)\pm\frac{\sqrt[]{169}}{2} \\ x=-(3)/(2)\pm(13)/(2) \\ x_1=-(3)/(2)-(13)/(2)=-(16)/(2)=-8 \\ x_2=-(3)/(2)+(13)/(2)=(10)/(2)=5 \end{gathered}`

Answer:

The roots (or solutions) of the equation are:

x1 = -8

x2 = 5