Question

HELP?? WILL MEDAL, AND FAN
Find the x-intercepts of the parabola with vertex (-1,-108) and y-intercept (0,-105).
Write your answer in this form: (x1,y1),(x2,y2).
If necessary, round to the nearest hundredth.

Answer 1

i have the answer so far, can anyone just help me get the points out of
y=3x^2+2x-107???

Answer 2

long time since i done these...

Answer 3

:(((

Answer 4

y=3x^2+6x-105

Answer 5

got it

Answer 6

general form is y = ax^2 + bx + c
when x = 0 , y = -105

so c = -105

Answer 7

x coordinate of the vertex = -b / 2a = 1

the y coordinate of the vertex = -108

so -108 = a*1^2 + b - 105

Answer 8

so b = -2a
and
-108 = a + b - 105

a + b = -3
substitute b = -2a in the above:
a - 2a = -3
-a = -3
a = 3

now finding b:
b = -3 -3 = -6

so equation is

3x^2 - 6x - 105 = 0

solve to find the x intercepts:

(3x - 21)(x + 5 ) = 0

x = 7 , -5

x intercepts are 7 and -5

Answer 9

you, but reverse the signs and its correct

Answer 10

(5,0),(-7,0)

Answer 11

ik