Answer:
The percent of the people who tested positive actually have the disease is 38.64%.
Step-by-step explanation:
Denote the events as follows:
<em>X</em> = a person has the disease
<em>P</em> = the test result is positive
<em>N</em> = the test result is negative
Given:

Compute the value of P (P|X) as follows:

Compute the probability of a positive test result as follows:

Compute the probability of a person having the disease given that he/she was tested positive as follows:

The percentage of people having the disease given that he/she was tested positive is, 0.3864 × 100 = 38.64%.
Problem:
Solve
2
x
+
5
y
=
−
3
;
3
x
−
y
=
21
Steps:
I will try to solve your system of equations.
3
x
−
y
=
21
;
2
x
+
5
y
=
−
3
Step: Solve
3
x
−
y
=
21
for y:
3
x
−
y
+
−
3
x
=
21
+
−
3
x
(Add -3x to both sides)
−
y
=
−
3
x
+
21
−
y
−
1
=
−
3
x
+
21
−
1
(Divide both sides by -1)
y
=
3
x
−
21
Step: Substitute
3
x
−
21
for
y
in
2
x
+
5
y
=
−
3
:
2
x
+
5
y
=
−
3
2
x
+
5
(
3
x
−
21
)
=
−
3
17
x
−
105
=
−
3
(Simplify both sides of the equation)
17
x
−
105
+
105
=
−
3
+
105
(Add 105 to both sides)
17
x
=
102
17
x
17
=
102
17
(Divide both sides by 17)
x
=
6
Step: Substitute
6
for
x
in
y
=
3
x
−
21
:
y
=
3
x
−
21
y
=
(
3
)
(
6
)
−
21
y
=
−
3
(Simplify both sides of the equation)
Answer:
y
=
−
3
and
x
=
6
Hey there! I'm happy to help!
To turn a fraction into a decimal, you simply divide the numerator by the denominator!
1÷3=0.3333333333.... (the 3s never end!)
Have a wonderful day! :D
The answer is 14 plants.
Explanation:
She already has 4 plants. She adds 9 more plants to the 4 plants. She will have 13 plants. And then she adds 1 plant to the 13 plants. She has now 14 plants.
Hope it helps!
Since there are 21 questions and one is extra credit, the fraction is 21/20. Divide it to get 1.05. In percent, this is 105%. Hope this helps!