Question

Help with either of these questions please. Also it’s apart of a homework practice

Answer 1

1. As we need the zeros to be on 4 and -7, the factored expression must be:

`(x-4)(x+7)`

And by multiplying

`x^2+7x-4x-28`
`x^2+3x-28`

2. By using the quadratic formula we get:

`\frac{-8\pm\sqrt[]{8^2-4\cdot4\cdot7}}{2\cdot4}`
`\frac{-8\pm\sqrt[]{64^{}-112}}{8}`
`\frac{-8\pm\sqrt[]{-48}}{8}`
`(-8)/(8)\pm\frac{\sqrt[]{-48}}{8}`
`-1\pm\frac{\sqrt[]{16\cdot3\cdot-1}}{8}`
`-1\pm\frac{\sqrt[]{16}\cdot\sqrt[]{3}\cdot\sqrt[]{-1}}{8}`
`-1\pm\frac{4\cdot\sqrt[]{3}\cdot i}{8}`
`-1\pm\frac{\cdot\sqrt[]{3}\cdot i}{2}`
`-1\pm\frac{i\cdot\sqrt[]{3}}{2}`