Which of the graphs below correctly solves fo

Question

iwanttogotostanford · Answer

@jhonyy9 @zepdrix

mathmate · Answer

Look for the graph that shows y=-x-4  (straight line sloping down)
and
y=-x^2-3x-1  (parabola concave downwards).

mathmate · Answer

There are sufficient hints to find the answer for this particular problem!
Please re-read previous posts!  :)

jhonyy9 · Answer

−x^2 − 3x − 1 = -x -4

so from these result what quadratic equation ?

jhonyy9 · Answer

will result 

x^2 +2x -3 =0 what can factorize it

(x+3)(x-1) =0

do you can solve it now ?

iwanttogotostanford · Answer

do i factor?

iwanttogotostanford · Answer

x^2-1+3x-3 ? @jhonyy9

jhonyy9 · Answer

this is the text of your exercise 

Which of the graphs below correctly solves for x in the equation −x^2 − 3x − 1 = −x − 4?

jhonyy9 · Answer

will result 

x^2 +2x -3 =0 what can factorize it

(x+3)(x-1) =0

do you can solve it now ?

jhonyy9 · Answer

just make x+3=0 and solve it for x 
and x-1=0 and solve it for x 

so how will get the x_1 and x_2 equales ?

iwanttogotostanford · Answer

so X= 1 and x=-3 @jhonyy9

iwanttogotostanford · Answer

@jim_thompson5910

iwanttogotostanford · Answer

@campbell_st

campbell_st · Answer

well here is a quick method... 
the line y = -x -4 

where does it cut the y-axis...?

the slope is negative

and what you you know about the concavity of 

$$y = -x^2$$

using those 3 pieces of infomration you can get the solution without having to do any major calculations.

iwanttogotostanford · Answer

@Nnesha

iwanttogotostanford · Answer

@wolf1728 @tori1423

stacey · Answer

Take the equation that you are given and separate it into two equations:
$$y=-x^{2}-3x-1$$$$y=-x-4$$
Then look at the graphs and see which one has both of those graphed.

iwanttogotostanford · Answer

@stacey thank you, finally someone who made some sense!