Answer:
Step-by-step explanation:
5x + 2y = -3
3x + 3y = 9
15x + 6y = -9
-15x - 15y = -45
-9y = -54
y = 6
5x + 2(6) = -3
5x + 12 = -3
5x = -15
x = -3
(-3, 6)
Answer:
Step-by-step explanation:
r = 7 cm
h = 15cm
pi = 3.14
Top and bottom (These questions drive you crazy when you don't know if there is both a top and bottom).
Area = 2* pi *r^2 = 2 * 3.14 * 7^2
Area = 2 * 3.14 * 49
Area = 307.72 Don't round this.
Cylinder body
Cylinder body = Circumference * h = 2*pi * r * h
Cylinder body = 2* 3.14 * 7 * 15
Cylinder body = <u> 659.4</u>
<u />
Total = 967.12
Rounded 967.1 Answer
X = amount of the 18% solution
y = amount of the 40% solution
we know the 18% solution has only 18% of alcohol, the rest is maybe water or something, now, how many liters is 18%? well, 18% of anything is just (18/100) * anything, so, 18% of x is just (18/100) *x or 0.18x, and that's how many liters are there.
likewise, how many liters are there in the 40% solution? well, (40/100) * y, or 0.4y, that many.
we know the mixture has to yield 10 liters at 20% alcohol, how many liters of only alcohol is that? well, (20/100) * 10, or 2 liters.


how much of the 40% solution? well y = 10 - x
The answer is clearly b makes the most sense