Answer:
a = 2, b = -9, c = 3
Step-by-step explanation:
Replacing x, y values of the points in the equation y = a*x^2 + b*x +c give the following:
(-1,14)
14 = a*(-1)^2 + b*(-1) + c
(2,-7)
-7 = a*2^2 + b*2 + c
(5, 8)
8 = a*5^2 + b*5 + c
Rearranging:
a - b + c = 14
4*a + 2*b + c = -7
25*a + 5*b + c = 8
This is a linear system of equations with 3 equations and 3 unknows. In matrix notation the system is A*x = b whith:
A =
1 -1 1
4 2 1
25 5 1
x =
a
b
c
b =
14
-7
8
Solving A*x = b gives x = Inv(A)*b, where Inv(A) is the inverse matrix of A. From calculation software (I used Excel) you get:
inv(A) =
0.055555556 -0.111111111 0.055555556
-0.388888889 0.444444444 -0.055555556
0.555555556 0.555555556 -0.111111111
inv(A)*b
2
-9
3
So, a = 2, b = -9, c = 3
We may have this planned like this:
two years is 8 quarters
<span>Assuming simple interest, </span>
You will use the formula
<span>A = P(1+rt) </span>
<span>= 400(1+8*.03) </span>
<span>= 496
</span>I think this is the answer:) Hope it helps a lot
Answer:
C. 36
Step-by-step explanation:
There are 217 students and 35 adults.
217 + 35 = 252 people
There are 7 buses for 252 people
252 people ÷ 7 buses = 36 people per bus
First you need to distribute the -8
So you would get -8x-8 now distribute the 3 so it would be 3x-6
-8x-8+3x-6=-3+2 is how it should look
Now combine the -8x and 3x cause their like terms and also -8 and -6
-5x-14=-3x+2 now add -3 to both sides
-2x-14=2 and add 14 to both sides
-2x=12 all left to do is divide both by -2
X=-6
