The formula for finding time is the distance divided by the velocity.So the answer is 100÷30=3.3333...
Parenthesis first
11+4=15
division second
15/3=5
what is the square root of 64? 8!
8x5=40
Answer is 40
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
Answer:
x=1
y=-1/2
Step-by-step explanation:
x+2y=0....(1)
10y=-5.....(2)
From (2) we can find y.
y=-5/10
y=-1/2
Use that in (1)
x+2*(-1/2)=0
x-1=0
x=1
