Question

a Decimal Answer AM કરી છે on 2x2 + 14x - 6 = x2 + 7x to the nearest tenth. Submit Answer attempt i out

Answer 1

Starting with the equation:

`2x^2+14x-6=x^2+7x`

Substract 7x from both sides:

`\begin{gathered} 2x^2+14x-6-7x=x^2 \\ \Rightarrow2x^2+7x-6=x^2 \end{gathered}`

Substract x squared from both sides:

`\begin{gathered} 2x^2+7x-6-x^2=0 \\ \Rightarrow x^2+7x-6=0 \end{gathered}`

Use the quadratic formula to find the values of x:

`\begin{gathered} x=\frac{-7\pm\sqrt[]{7^2-4\cdot(1)\cdot(-6)}}{2\cdot(1)} \\ =\frac{-7\pm\sqrt[]{49+24}}{2} \\ =\frac{-7\pm\sqrt[]{73}}{2} \end{gathered}`

Use a calculator to find both values of x:

`\begin{gathered} x_1=\frac{-7+\sqrt[]{73}}{2}_{} \\ =0.7720018727\ldots \\ \approx0.8 \end{gathered}`
`\begin{gathered} x_2=\frac{-7-\sqrt[]{73}}{2} \\ =-7.772001873\ldots \\ \approx-7.8 \end{gathered}`