Answer:
A. (–8, 2)
Step-by-step explanation:
(1) y = ½x + 6
(2) y = -¾x – 4 Set (1) = (2)
½x + 6 = -¾x – 4 Multiply each side by 4
2x + 24 = -3x – 16 Add 16 to each side
2x + 40 = -3x Subtract 2x from each side
40 = -5x Divide each side by -5
(3) x = -8 Substitute (2) into (1)
y = ½(-8) +6
= -4 + 6
= 2
The solution to the system of equations is (-8 ,2).
You can see the graphs of the two functions in the figure below. The two lines intersect at (-8, 2).
Check:
2 = ½(-8) + 6 2 = -¾(-8) - 4
2 = -4 +6 2 = 6 - 4
2 = 2 2 = 2
Answer: 4.8 ounces
Step-by-step explanation:
In total there are 12 ounces. If she drinks 3/5 of 12 you multiply 3/5 by 12.
3/5 * 12 would be equal to 3/5 * 12/1 which is 36/5. You have found how much she has drank. 36/5 is also equal to 7.2 ounces. Subtract 7.2 form 12 and you get 4.8 ounces.
Hope this helped!
Try this:
1) note that weight of pure antifreeze before mixing and after mixing is the same. So, if 'x' is weight of pure antifreeze in 50% solution, it is possible to make up equation before mixing: 0.5x+0.2*90.
2) there are 0.2*90=18 gal. of pure antifreeze in the 20% solution. If 'x' gal. is the weight of pure antifreeze in 50% sol. and 18 gal. is the weight of pure antifreeze in 20% sol., it is possible to make up an equation after mixing: 0.4(x+18).
3) using the both parts: 0.5x+0.2*90=0.4(x+18) ⇒ x=54 gal. of <u>pure</u> weight.
4) to find 50% solution of 54 gal. pure weight just 54:0.5=108 gal.
Answer: 108 gal.
Alternate Interior Angles
Answer:
The mean of the sampling distribution is 20 and the standard deviation is 2.89.
Step-by-step explanation:
The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean 
and standard deviation 
, the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean and standard deviation 
.
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
Population:
Mean 20, standard deviation of 5.
Sampling distribution:
3 rounds
Mean = 20
The mean of the sampling distribution is 20 and the standard deviation is 2.89.
