X + y = 20 --> eqn 1
The second equation would be the mass balance shown below:
(x)(0.40) + y(0.70) = 20(0.52) --> eqn 2
Rearranging eqn 1,x = 20 - ySubstitute this to eqn 2:
(20 - y)(0.40) + y(0.70) = 20(0.52)Solve for y,y = 8 grams Finally, solve for x.x = 20 - 8 = 12 grams
Therefore, Serena needs 12 grams of the 40% solution and 8 grams of the 70% solution.
Answer:
Diameter = 12 ft.
Step-by-step explanation:

Hope this helps!
(::)
brainliest?
Answer:
7√2
Step-by-step explanation:
Thank to the give angle we can say that the two legs are congruent
b = 
98/2 = 49
49/7 = 7
7/7 = 1
98 = 7^2 x 2
√98 = 7√2
Answer is <span> 4(4 + 9) (first choice)
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