Question

Fine ONE of the zeros of F(x) =4x^2 + 16x -20

Answer 1

(Make sure to set f(x) to zero)

For this, I will be completing the square. Firstly, add 20 to both sides of the equation:
`20=4x^2+16x`

Next, divide both sides by 4:
`5=x^2+4x`

Next, we want to make the right side of the equation a perfect square. To do that, divide the x coefficient by 2 and square that quotient. In this case:

4 ÷ 2 = 2, 2² = 4

Add four to both sides of the equation:
`9=x^2+4x+4`

Next, factor the right side of the equation:
`9=(x+2)^2`

Next, square root both sides of the equation:
`\pm 3=x+2`

Lastly, subtract 2 to both sides of the equation and your answers are:

`-2\pm 3=x\\1,-5=x`