Answer:
x = -6 x= -3
Step-by-step explanation:
f(x) = x^2+9x+18
Set equal to 0 to find the zeros
0 = x^2+9x+18
Factor, what numbers multiply to 18 and add to 9
6*3 =18
6+3=9
0= (x+6) (x+3)
Using the zero product property
x+6 =0 x+3 =0
x = -6 x= -3
Step-by-step explanation:
From the statement:
M: is total to be memorized
A(t): the amount memorized.
The key issue is translate this statement as equation "rate at which a subject is memorized is assumed to be proportional to the amount that is left to be memorized"
memorizing rate is 
.
the amount that is left to be memorized can be expressed as the total minus the amount memorized, that is 
.
So we can write
And that would be the differential equation for A(t).
The key with these problems is to find which function has the closest y-intercept to the graph, and then try to figure out which one best approximates the slope.
Here are our options:
<span>A. y = x + 4
B. y = 4x + 9
C. y = x + 18
D. y = 3x + 22
Which has the closest approximation of the y-intercept?
The y-intercept is not directly given, but we can assume it is less than 10.
That leaves us with A and B.
Which has the closest approximation of the slope?
The graph, on average, seems to move up about 60 and over about 15.
Slope = rise/run = 60/15 = 4. Although the slope isn't exactly 4, it's much closer to 4 than 1, which is slope for option A.
Therefore, the answer is
B) y= 4x + 9
</span>
<span>644.240741
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