Question

How do I complete the square for 4x^2+ 8x-5= 0?

Answer 1

x =
`(1)/(2)`, -
`(5)/(2)`

Explanation:

This is not so fun!

`4x^(2) + 8x - 5 = 0\\`

Step 1: Move the 5 to the right side

`4x^(2) +8x = 5`

Step 2: Divide thru by 4

`x^(2) + 2x = (5)/(4)`

Step 3: Divide 2 (from 2x) by 2 and square the result and add that to both sides of the equation.

2/2 = 1 1 squared = 1

`x^(2) + 2x + 1 = (5)/(4) +1 = (9)/(4)`

Step 4: Factor the left side

`(x + 1)^(2) = (9)/(4)`

Step 5: Take the square root of both sides

x + 1 = ±
`\sqrt{(9)/(4) }` = ±
`(3)/(2)`

Step 6: Move the 1 to the right side and add the results

x = -1 ±
`(3)/(2)` = -1 +
`(3)/(2)` or -1 -
`(3)/(2)`

=
`(1)/(2)` or -
`(5)/(2)`

And bingo, you have the solutions by completing the square. Lot of fun, huh.

Answer 2

man I have no idea dude I don't really know squares if you're talking about square root I really don't know