Answer:
<h3>
The minimum score speech to get a B+ is 89.</h3>
Step-by-step explanation:
Average of the first 3 = 85 + 77 + 81 / 3
= 243 / 3
= 81
The fourth score ( to get 85 ) = 81 + 89
= 170 / 2
= 85
Here i how I would do it:<span>f(x)=−<span>x2</span>+8x+15</span>
set f(x) = 0 to find the points at which the graph crosses the x-axis. So<span>−<span>x2</span>+8x+15=0</span>
multiply through by -1<span><span>x2</span>−8x−15=0</span>
<span>(x−4<span>)2</span>−31=0</span>
<span>x=4±<span>31<span>−−</span>√</span></span>
So these are the points at which the graph crosses the x-axis. To find the point where it crosses the y-axis, set x=0 in your original equation to get 15. Now because of the negative on the x^2, your graph will be an upside down parabola, going through<span>(0,15),(4−<span>31<span>−−</span>√</span>,0)and(4+<span>31<span>−−</span>√</span>,0)</span>
To find the coordinates of the maximum (it is maximum) of the graph, you take a look at the completed square method above. Since we multiplied through by -1, we need to multiply through by it again to get:<span>f(x)=31−(x−4<span>)2</span></span><span>
Now this is maximal when x=4, because x=4 causes -(x-4)^2 to vanish. So the coordinates of the maximum are (4,y). To find the y, simply substitute x=4 into the equation f(x) to give y = 31. So it agrees with the mighty Satellite: (4,31) is the vertex.</span>
Answer:
D
Step-by-step explanation:
not good at explaining i just think its D
Answer:
X = 2(3x + 4)
the rest i dont know sorry D:
The symbol they are using is that of a ray so, order matters.
Ray BC is telling you the ray starts at point B like a line segment BUT continues on towards and through point C rather than stopping at it.
Ray CB is telling you just the opposite; the ray starts at point C, continues on towards and through point B.