Q = (c + d) / 2.....when d = 5 and Q = 21
21 = (c + 5) / 2 ...multiply both sides by 2
2 * 21 = c + 5
42 = c + 5
42 - 5 = c
37 = c <== answer A
Answer:
<u>f(x) = 2(x - 2)^2 - 1</u>
<u>vertex: (2, -1)</u>
Step-by-step explanation:
f(x) = 2x^2 - 8x + 7
<em>First, we find the vertex. </em>
x = -(-8)/4 = 2
y = 2(2)^2 - 8(2) + 7 = 2(4) - 16 + 7 = 8 - 9 = -1
vertex: (2, -1)
<em>Second, we write f(x) in vertex form. </em>
<em>we know that h and k have to be 2 and -1. </em>
2x^2 - 8x + 7 = a(x - 2)^2 - 1
<em>Since 8 - 1 = 7, we do this: </em>
f(x) = (2x^2 - 8x + 8) - 1
<em>Factor out the 2 and then factor the polynomial</em>
f(x) = 2(x^2 - 4x + 4) - 1
<em>factors of 4: </em>
1 4
2 2
-1 -4
<u>-2 -2 = -4</u>
<em>the function in vertex for is: </em>
f(x) = 2(x - 2)^2 - 1
Her rate of commission being 8% on an amount of $4,500, then her commission in $ will be :
8% x 4500 = 0.08 x 4500 = $360
So her commission = $360
