Question

What are the exact solutions of x2 − 5x − 7 = 0?

x = the quantity of negative 5 plus or minus the square root of 3 all over 2

x = the quantity of 5 plus or minus the square root of 3 all over 2

x = the quantity of negative 5 plus or minus the square root of 53 all over 2

x = the quantity of 5 plus or minus the square root of 53 all over 2

Answer 1

What do you get when you factor that trinomial?

Answer 2

idk

Answer 3

Have you seen the "quadratic formula?"

Answer 4

It's just "un-FOILing". You need to write \(x^2 − 5x − 7 \) as a product (multiplication) of two binomials:

\(\Large x^2 − 5x − 7 =(....?....)(....?....)\)

so you need to figure out what goes in the ( )'s. Since the trinomial starts with an \(x^2\) without a coefficient in front of it, you KNOW it has to be:

\(\Large x^2 − 5x − 7 =(x\pm ?)(x\pm ?)\)

So all you need is to figure out the LAST terms, and the signs in the middle.

Answer 5

oh wait, may bad.... @skullpatrol is right. Need the QF on this one.

Answer 6

*my

Answer 7

I hadn't looked at the answers... lol.

Answer 8

still don't get it

Answer 9

You have \(\Large x^2 − 5x − 7 =0\)

That's of the form \(\Large ax^2 +bx +c =0\)

For YOUR equation, what is a, b and c?

a= ?
b= ?
c= ?

Answer 10

okay