Answer:
Which one ?
Step-by-step explanation:
Answer:
see explanation
Step-by-step explanation:
the sum to n terms of an arithmetic sequence is
=
[2a + (n - 1)d ]
where d is the common difference and a is the first term
here d = 9 - 7 = 7 - 5 = 2 and a = 5, hence
=
[(2 × 5) + 2(n - 1) ]
=
(10 + 2n - 2)
=
(2n + 8)
= n² + 4n
When sum = 165, then
n² + 4n = 165 ← rearrange into standard form
n² + 4n - 165 = 0 ← in standard form
(n + 15)(n - 11) = 0 ← in factored form
equate each factor to zero and solve for n
n + 15 = 0 ⇒ n = - 15
n - 11 = 0 ⇒ n = 11
but n > 0 ⇒ n = 11
Answer:
51.877 kg
Step-by-step explanation:
a
See attachment for calculations
b
The amount of salt in the tank after 4 hours is gotten by simply replacing t in the equation from a, with 4 hours. Since the t gotten in a above is in minutes, we'd convert hours to minute as well. If we do that, we have
t = 4 hours = 4 * 60 minutes = 240 minutes
y = 160/3 (1 - e^((-3 * 240)/200))
y = 160/3 (1 - e^(-720/200))
y = 160/3 (1 - 0.0273)
y = 160/3 (0.9727)
y = 51.877 kg
Therefore, the amount of salt in the tank after 4 hours is 51.877 kg
Answer:
Suppose we have a random number A.
The multiplicative inverse of A is a number X such that:
A*X = 1
When we work with real numbers, X = 1/A
Then:
A*(1/A) = A/A = 1
This means that (1/A) is the multiplicative inverse of A.
Where we need to have A ≠ 0, because we can not divide by 0.
Now we want to find the multiplicative inverse of the numbers:
2: Here the inverse is (1/2) = 0.5
1/5: Here the inverse is (1/(1/5)) = (5/1) = 5
-4: Herre the inverse is (1/(-4)) = -(1/4) = -0.25
(3x+2) (x-7)
FOIL
first 3x*x = 3x^2
outer 3x*-7 = -21x
inner = 2*x = 2x
last 2*-7 = -14
add them together = 3x^2 -21x+2x -14
combine like terms 3x^2 -19x -14