Question

What mistake did Richard make? Explain what he needs to do to fix it.

Answer 1

Given:-

`x^2-6x+8=0`

To find the simplified form and the mistake.

So now we use the formula,

`x=\frac{-b\pm\sqrt[]{b^2-4ac}}{2a}`

So now we substitute the value. so we get,

`\begin{gathered} x=\frac{-b\pm\sqrt[]{b^2-4ac}}{2a} \\ x=\frac{6\pm\sqrt[]{6^2-4*1*8}}{2*1} \\ x=\frac{6\pm\sqrt[]{36-32}}{2*1} \\ x=\frac{6\pm\sqrt[]{4}}{2*1} \\ x=(6\pm2)/(2) \end{gathered}`

So now we get,

`\begin{gathered} x=(6\pm2)/(2) \\ x=(6+2)/(2),x=(6-2)/(2) \\ x=(8)/(2),x=(4)/(2) \\ x=4.x=2 \end{gathered}`

So the value of x is,

`4,2`

So the mistake is in step 5.