Answer:
- c = -4.5
- z = 20
- x = -12
- a = -4/7
Step-by-step explanation:
A way to do this that will always work is ...
- eliminate parenthses and collect terms
- subtract any constants from the left side
- subtract any variable terms from the right side
- divide by the coefficient of the variable
1.
- 8c -11 -6c = -2
- 2c -11 = -2
- 2c = 9
- c = 4.5
2.
- 3z +4 -2z -9 = 15
- z -5 = 15
- z = 20
3.
- 12 -4x +18 = 36 +4x +18 -6x
- 30 -4x = 54 -2x
- -4x = 24 -2x
- -2x = 24
- x = -12
4.
- 36a -9a -5 = 6a -17
- 27a -5 = 6a -17
- 27a = 6a -12
- 21a = -12
- a = -12/21 = -4/7
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
I believe that the answer is C sorry if it is wrong.
Answer: 36 cm
Explanation: Use Pythagorean Theorem to solve the question: a^2+b^2=c^2
Answer:
M= D x V, V= M x D
Step-by-step explanation:
You just do the opposite of division since the original is:
Density= Mass/ Volume
