Question

What is the x-coordinate of the vertex of the parabola whose equation is y = 3x2 + 9x?

Answer 1

the x-coordinate of the vertex of y = ax^2 + bx + c is given by:
x = -b/(2a).

Answer 2

y = 3x^2 + 9x = 3x^2 + 9x + 0

Answer 3

a = 3, b = 9, and c = 0

Answer 4

the x-coordinate of the vertex is:
x = -b/(2a) = -9/[2(3)] = -3/2 = -1 1/2

Answer 5

-3
-1
-
this are the answer choices @EllenJaz17

Answer 6

What's the last option? It's just a negative sign

Answer 7

no its -2 over 3 -2/3

Answer 8

and so is the second answer is -1 and 1 over 2 somethuing like this -1 1/2

Answer 9

Its -3/2

Answer 10

y = 3x^2 + 9x

y = 3(x^2 + 3x + 9/4) - 27/4

y = 3(x + 3/2)^2 - 27/4

From this, we can see a low point and vertex when:

x = -3/2 because that's when the first term is smallest.

So,

x = -3/2

Answer 11

thanks:)