## zarkam21 one year ago Help, will medal =)

1. zarkam21

2. anonymous

One answer is c, and you can see how i got that here http://www.tiger-algebra.com/drill/x2-3x-4=0/ I actually think the only answer is c

3. zarkam21

How sure are you about the only answer being C because I really need to get this question correct.

4. zarkam21

@jcoury

5. anonymous

Well that's the one i know of and when i worked it out that's what i got you may want to do it yourself to compare

6. anonymous

And E! which is 4 like in the link

7. Michele_Laino

hint: you have to apply this formula: $\Large x = \frac{{ - b \pm \sqrt {{b^2} - 4 \times a \times c} }}{{2 \times a}}$ where: a=1, b=-3, c=-4 what do you get?