Answer:

Step-by-step explanation:
m²-2mn+n²-9r

Adding two or more vectors is correct.
Answer: 39
Step-by-step explanation:
SInce the problem asks for the expression when a=2 and d=5, you olug in the values of a and d and solve.
(5)²+3(2)+6+(2) [exponent]
25+3(2)+6+2 [multiply]
25+6+6+2 [add]
39
After plugging in a=2 and d=5, we got 39 as our answer.
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