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
Answer:
$3.25
Step-by-step explanation:
Given that:
Mean, λ = 1.4
Strike within next minute = $3 won
Strike between one and 2 minutes = $5
Strike more than 2 minutes = $1
Probability that next strike occurs within the next minute :
Using poisson :
P(x < 1) = 1 - e^-(λx) ;
P(x < 1) = 1 - e^-(1.4*1) = 1 - e^-1.4
P(x < 1) = 1 - 0.2465969
P(x < 1) = 0.7534030
Next strike occurs between 1 and 2 minutes :
(1 < x < 2) :
P(x < 2) - P(x < 1)
P(x < 2) = 1 - e^-(λx) ;
P(x < 2) = 1 - e^-(1.4*2) = 1 - e^-2.8
P(x < 2) = 1 - 0.0608100
P(x < 2) = 0.9391899
P(x < 2) - P(x < 1)
0.9391899 - 0.7534030 = 0.1857869
P(striking after 2 minutes)
P(x > 2) = e^-(λx) ;
P(x > 2) = e^-(1.4*2) = e^-2.8
P(x > 2) = 0.0608100
Amount charged :
(0.7534030 * 3) + (0.1857869 * 5) + (0.06081 * 1)
= 3.2499
= $3.25
So, the function is obviously shifted up by 1 so it rules out A and B, and we also see that the period is 4pi rather than 2pi, and using the fact that:
Now that we know our b value, we see that the correct answer would be C.
Answer:
Adele's current age is 12
Step-by-step explanation:
Let a = Adele's current age
Let t = Timothy's current age
Adele is 5 years older than Timothy:
a = t + 5 {equation 1}
In 3 years Timothy will be 2/3 of Adele's age:
(2/3)(a + 3) = t + 3 {equation 2}
Since we are looking for Adele's age, let's rearrange equation 1 to:
t = a - 5
Substitute that into equation 2 and solve for a.
(2/3)(a+3) = a - 5 + 3
(2/3)(a + 3) = a - 2
Multiply through by 3 to clear the fraction
2(a+3) = 3a - 6
2a + 6 = 3a - 6
Add 6 to both sides, subtract 2a from both sides
12 = a
Adele is 12 years old
This means Timothy is 7 years old.
Check equation 2 to verify:
(2/3)(a + 3) = t + 3
(2/3)(12+3) = 7 + 3
(2/3)(15) = 10
10 = 10
Answer:
Frequency: 20
A.F: 650
Mean: 30
Step-by-step explanation:
Frequency and A.F were just sums of the values mentioned for each
The mean:
Definition: the average of a data.
Formula: sum of numbers divided by the number of numbers
Answer: (28 x 2 + 29 x 4+ 30 x 8 + 31 x 4+ 32 x 2) divided by 20 = 30
Hope this helps
