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:
Step-by-step explanation:
Answer:
b/(b+a)
Step-by-step explanation:
(1/a)-(1/b) :[ (b²-a²)/ab²]
first solve :
common denominator ab
(1/a)-(1/b) = (b-a)/ab
[b-a/ab] : [(b²-a²)/ab²]
when divide fraction ( division sign turn to (×) and flip the second fraction(reciprocal):
[b-a/ab] × [ab²/ (b²-a²)]
then simplify : ab²/ab = b
(b-a)×(b/b²-a²)
factorize : b²-a² = (b-a)(b+a)
(b-a)×(b/(b-a)(b+a)) simplify : (b-a)/b-a = 1
[(b-a)(b)]/[(b-a)(b+a)
b/b+a
Answer:
1
Step-by-step explanation:
there were 5 pieces now there is 4. so 4 slices of pizza divided by 4 is 1
13pi/12 lies between pi and 2pi, which means sin(13pi/12) < 0
Recall the double angle identity,
sin^2(x) = (1 - cos(2x))/2
If we let x = 13pi/12, then
sin(13pi/12) = - sqrt[(1 - cos(13pi/6))/2]
where we took the negative square root because we expect a negative value.
Now, because cosine has a period of 2pi, we have
cos(13pi/6) = cos(2pi + pi/6) = cos(pi/6) = sqrt[3]/2
Then
sin(13pi/12) = - sqrt[(1 - sqrt[3]/2)/2]
sin(13pi/12) = - sqrt[2 - sqrt[3]]/2
