Question

The line of symmetry for the quadratic equation y = ax2 + 8x - 3 is x = 4. What is the value of "a"?

Answer 1

the line of symmetry for a quadratic written in standard form is \(\large x=-\frac{b}{2a} \)

Answer 2

plug in those values in for x and b then solve for a.

Answer 3

these are the choices that i have
-2
-1
1

I did the substitution and solved but ended up with 16a = -29
a = -1.8125
so, is it -2 in approximation??

Answer 4

x=4 and b=8... plug this into \(\large x=-\frac{b}{2a} \). solve for a...

Answer 5

I got -1

Answer 6

???

Answer 7

that's what i got...

Answer 8

ok thanks :)

Answer 9

yw...:)