He will mix some 20% solution and some 70% solution to make 60% solution.
Let x = number of liters of 20% solution.
Let y = number of liters of 70% solution.
He wants to make 50 liters of 60% solution, so
x + y = 50 First Equation
The amount of acid in x amount of 20% solution is 20% of x, or 0.2x
The amount of acid in y amount of 70% solution is 70% of y, or 0.7y
The amount of acid in 50 liters of 60% solution is 60% of 50 liters, or 0.6 * 50 = 30
Now we add the amounts of acid.
0.2x + 0.7y = 30 Second Equation
x + y = 50
0.2x + 0.7y = 30
-0.2x - 0.2y = -10
0.2x + 0.7y = 30
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0.5y = 20
y = 40
x + y = 50
x + 40 = 50
x = 10
Answer: He needs 10 liters of 20% solution and 40 liters of 70% solution.
When simplified, y=2(x+4)+5 equals y=2x+13
They are similar because they both are triangles. But they are not the same size.
Y = yearbook club
d = drama club
y + d = 84
d = y + 16
now we sub y + 16 in for d in the first equation
y + d = 84
y + (y + 16) = 84
2y + 16 = 84
2y = 84 - 16
2y = 68
y = 68/2
y = 34 <=== yearbook club students
d = y + 16
d = 34 + 16
d = 50 <=== drama club students
