Answer: choice A. 40 liters
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Explanation:
x = number of liters of the 50% alcohol solution
If we have x liters of 50% alcohol, then we have 0.50*x liters of pure alcohol. This is added to 0.90*40 = 36 liters of pure alcohol (from the 90% solution).
So far we have 0.50*x + 36. This expression represents the total amount of pure alcohol. We want a 70% solution, so we want 70% of the total 40+x meaning 0.50*x + 36 is to be set equal to 0.70*(40+x) and we solve for x as shown below
0.50*x + 36 = 0.70*(40+x)
0.50*x + 36 = 0.70*(40)+0.70*(x)
0.50*x + 36 = 28+0.70*x
36 - 28 = 0.70*x - 0.50x
8 = 0.20x
0.20x = 8
x = 8/0.20
x = 40
So that is why the answer is choice A. 40 liters
Top right, it’s really easy just. Count the numbers
Answer:
Two boxes will cost 
The cost of one tile is approximately 
Step-by-step explanation:
Note that 1 ft = 12 in, then
The area of the floor is
Now
then
144 sq. in - 1 tile,
9540 sq. in - x tiles.
Mathematically,
tiles is needed to cover the floor (67 full tiles).
Each box of tiles contains 45 tiles, so Cristina has to buy 2 boxes. These two boxes will cost The cost of one tile is approximately
Answer: -1x - 1
Step-by-step explanation:
2 -1x -3
2-3 = -1
-1x - 1
Answer:
Complementary angles sum to 90°.
<u>∠X has </u><u>∠P </u><u>complementary to it as:</u>
