anonymous one year ago find the axis of symmetry for y=3x^2+5x-7 a)x=5 b)x=-5/3 c)x=-7 d)x=-5/6

1. Loser66

What is the x coordinate of the vertex?

2. anonymous

it dosnt give me one

3. Loser66

sure, you have to find it out

4. Loser66

by formula x = -b/2a

5. anonymous

huh im so sorry im wakeful at this lol

6. anonymous

awful*

7. anonymous

$y =3x^2+5x -7$ do you know how to do the completing the square? Look at the attachment, it briefly shows you how to do it. So If I complete the square given in the question then it will be $y = 3(x + \frac{ 5 }{ 3 })^2-\frac{ 25 }{ 9 } - 7$ the x you see in this equation has to be to which if you add 5/3 will give you 0 Sp bring 5/3 to the other side $x = -\frac{ 5 }{ 3 }$ back to the original equation so when x is -5/3 your y will be: $y = -\frac{ 88 }{ 9 }$ the x is the line of symmetry |dw:1433012607952:dw|

8. anonymous

I didn't check the discriminant so Idk if the parabola is having any x-intercept btw what @Loser66 said is correct I simply gave you the explanation for the formula

9. Loser66

@nopen x = -b/2a = - 5/6

10. anonymous

Oops the 6

11. anonymous

lol

12. Loser66

hehehe.. you got it.