Answer:
I am sorry I need points I am really sorry
The answer would be -5 because then you can do the opposite, 0+5 which would equal 5
<h3>
Answer: 56 minutes</h3>
1 hour = 60 minutes
The time values given, in minutes, are:
25, 55, 60, 94, and 46
going from monday to friday in that exact order
Add up the values, then divide by 5. This is because there are 5 values
So adding up the values gets us: 25+55+60+94+46 = 280
Then dividing by 5 leads to this answer: 280/5 = 56
note: you must convert the "1 hour" to "60 minutes" because each time value must be in the same units. Otherwise, its like mixing apples and oranges which makes no sense.
Let
x = number of liters of the 40% salt solution
y = number of liters of the 20% salt solution
The two amounts (x and y) must combine to 1500 liters, so
x+y = 1500
we can solve for y to get
y = 1500-x
after subtracting x from both sides
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If we have x liters of the 40% salt solution (composed of pure salt plus other stuff) then we have exactly 0.40*x liters of pure salt. Simply multiply the decimal form of the percentage with the amount of solution.
Similarly, if we have y liters of the 20% solution, then we have 0.20*y liters of pure salt
Combined, we have 0.40*x + 0.20*y liters of pure salt all together.
We want 1500 liters of a 28% solution, so we want 1500*0.28 = 420 liters of pure salt
Equate the two expressions (0.40*x + 0.20*y and 420) to get
0.40*x + 0.20*y = 420
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We have the equation 0.40*x + 0.20*y = 420 and we also know that y = 1500-x
Let's use the substitution property now
0.40*x + 0.20*y = 420
0.40*x + 0.20*( y ) = 420
0.40*x + 0.20*( 1500 - x ) = 420 ... note how y is replaced with 1500-x
Now we can solve for x
0.40*x + 0.20*( 1500 - x ) = 420
0.40*x + 0.20*(1500) + 0.20*(-x) = 420
0.40*x + 300 - 0.20x = 420
0.40*x - 0.20x + 300 = 420
0.20x + 300 = 420
0.20x + 300 - 300 = 420 - 300
0.20x = 120
0.20x/0.20 = 120/0.20
x = 600
Now that we know x, use this to find y
y = 1500-x
y = 1500-600 ... plug in x = 600 (ie replace x with 600)
y = 900
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Answers:
We need 600 liters of the 40% solution
We need 900 liters of the 20% solution
The answer which would correctly fill in the blank on this statement is -4, because 1.7 x 10 ^ -4 = 0.00017
10^-4 = 0.0001, and when you multiply that by 1.7, that is 0.00017.