Answer:
A= -17
Step-by-step explanation:
A +-21 = -38
+21 +21
-38+21= -17
A= -17
Answer:
29.411 % of the result is true.
Step-by-step explanation:
This test's sensitivity is low.
Suppose we have 5 drug users and 85% of the test is accurate meaning that 5* 0.85= 4.25 people are drug users which is true.
But if work for the non users than 5% people being drug users means 95 people are non drug users out of the hundred.
And 85 % accuracy would give 95* 0.85= 80.75 which is very high.
And out of the 80.75 * 15%= 12.11 only 12 are positive .
The results give us 5 out of 17 true possibilities
or 5/17 *100= 29.411 % of the result is true.
This answer seems to be C
We can begin by rearranging this into multiplication:
Now we can factor the numerators and denominators:
The factors
(x+4) and
(x+2) cancel out, leaving us with:
Our answer comes out to be:
or
Based on the numerator of the second fraction (since we used its inverse), the denominators of both, and the factors we canceled out earlier, the restrictions are
x ≠ -4, -3, -2, -1, 4
<u>Zeros of the function</u>
f(x) = (x + 2)² - 25
f(x) = (x + 2)(x + 2) - 25
f(x) = x(x + 2) + 2(x + 2) - 25
f(x) = x(x) + x(2) + 2(x) + 2(2) - 25
f(x) = x² + 2x + 2x + 4 - 25
f(x) = x² + 4x + 4 - 25
f(x) = x² + 4x - 21
x² + 4x - 21 = 0
x = <u>-(4) +/- √((4)² - 4(1)(-21))</u>
2(1)
x = <u>-4 +/- √(16 + 84)</u>
2
x = <u>-4 +/- √(100)
</u> 2<u>
</u>x = <u>-4 +/- 10
</u> 2<u>
</u>x = -2 <u>+</u> 5<u>
</u>x = -2 + 5 x = -2 - 5
x = 3 x = -7
f(x) = x² + 4x - 21
f(3) = (3)² + 4(3) - 21
f(3) = 9 + 12 - 21
f(3) = 21 - 21
f(3) = 0
(x, f(x)) = (3, 0)
or
f(x) = x² + 4x - 21
f(-7) = (-7)² + 4(-7) - 21
f(-7) = 49 - 28 - 21
f(-7) = 21 - 21
f(-7) = 0
(x, f(x)) = (-7, 0)
<u>Vertex</u>
<u>X - Intercept</u>
<u />-b/2a = -(4)/2(1) = -4/2 = -2
<u>Y - Intercept</u>
y = x² + 4x - 21
y = (-2)² + 4(-2) - 21
y = 4 - 8 - 21
y = -4 - 21
y = -25
(x, y) = (-2, -25)
<u />
