9514 1404 393
Answer:
geometric sequence
Step-by-step explanation:
The terms of the sequence have a common ratio of -12/3 = -4, so the sequence is geometric. The general term is ...
an = 3(-4)^(n-1)
so the sum can be written as ...
(Note the summation starts at n=0, corresponding to a first term of 3.)
Answer:
- 33 1/3 liters of 30%
- 16 2/3 liters of 45%
Step-by-step explanation:
Let x represent the liters of 45% solution needed. Then the amount of HCl in the mix is ...
0.45x +0.30(50 -x) = 0.35(50)
0.15x = 0.05(50) . . . . . simplify, subtract 0.30(50)
x = (0.05/0.15)(50) = 50/3 = 16 2/3 . . . liters of 45% HCl
33 1/3 liters of 30% and 16 2/3 liters of 45% HCl are needed.
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<em>Comment on the solution</em>
You may notice that the general solution to a mixture problem of this sort is that the fraction of the mix that is the highest contributor is ...
(mix % - low %) / (high % - low %) = (.35 -.30) / (.45 -.30) = .05/.15 = 1/3
Answer:
(n-2) • (4n+3)
Step-by-step explanation:
4n2-5n-6
Final result :
(n - 2) • (4n + 3)
Step by step solution :
Step 1 :
Equation at the end of step 1 :
(22n2 - 5n) - 6
Step 2 :
Trying to factor by splitting the middle term
2.1 Factoring 4n2-5n-6
The first term is, 4n2 its coefficient is 4 .
The middle term is, -5n its coefficient is -5 .
The last term, "the constant", is -6
Step-1 : Multiply the coefficient of the first term by the constant 4 • -6 = -24
Step-2 : Find two factors of -24 whose sum equals the coefficient of the middle term, which is -5 .
-24 + 1 = -23
-12 + 2 = -10
-8 + 3 = -5 That's it
Step-3 : Rewrite the polynomial splitting the middle term using the two factors found in step 2 above, -8 and 3
4n2 - 8n + 3n - 6
Step-4 : Add up the first 2 terms, pulling out like factors :
4n • (n-2)
Add up the last 2 terms, pulling out common factors :
3 • (n-2)
Step-5 : Add up the four terms of step 4 :
(4n+3) • (n-2)
Which is the desired factorization
Final result :
(n - 2) • (4n + 3)
I just told you the answer it is -5
Answer:
which one
Step-by-step explanation:
the upper answer would be 38 and lower would be
