Answer:
3:7
Step-by-step explanation:
So to solve this problem, you have to understand what the ratio 1:4 and 2:3 means. The 1:4 ratio in the first equation means that for "each unit of alcohol" there is 4 of those units of water. So let's say I had 2 gallons of alcohol and mixed it with 8 gallons of water. This means for each gallon of alcohol, there is 4 gallons of water, or in other words a 1:4 ratio. This can be described as a percentage as well. For each 5 gallons there are 4 gallons of water, and 1 gallon of alcohol or <em>20%</em> is alcohol. So let's just say that x=alcohol and y=water, this means that: 
where c is the total amount in the glass. This means that: 
Let's do the same thing to the second equation. the ratio means that for every 2 units of alcohol there are 3 units of water. This means for every 5 gallons of the mixture there is 2 units of alcohol which is 40%. In this case let's also say that j=alcohol and k=water. This means that: 
and that: 
.
So if we're going to add the two glasses, we simply add the two sides, and get: 
. Now remember how can can express j and x in terms of c, since it's a certain percentage of c (the entire thing). This means that we get: 
Now we can add like terms to get the equation: 
. We can find how much 0.6c is to 2c by dividing the 2, in doing so we get that 0.6c/2c = 0.3, or in other words the 0.6c is only 30% of the final mixture, and since the 0.6c represents the alcohol in this mixture, that means that's the percentage of alcohol. To write this as a ratio, this means for every 3 units of alcohol, there is 7 units of water, because 3/10 = 30%.
Answer:
1 1/2 miles
Step-by-step explanation:
5/8+3/8 is 8/8, or 1 mile. She now has 1 1/2 miles left to go! (2 1/2-1=1 1/2)
Answer:
There are 3 adults in the family.
Step-by-step explanation:
The equations 8x + 4y = 32 and 16x + 12y = 72 represent the cost of lunch and dinner for a family in which x is the number of adults and y is the number of children.
We have to find the number of adults or the value of x by solving these equations.
equations are 8x + 4y = 32 -------(1)
16x + 12y = 72 --------(2)
Now we will multiply equation 1 by 3 and subtract it by equation 2.
(16x + 12y) -3(8x + 4y) = 72 - 96
16x + 12y - 24x - 12y = -24
(16x - 24x) + (12y - 12y) = -24
-8x = - 24
8x = 24
x = 3
Therefore, there are 3 adults in the family.
Problem
evaluate the function
f(-x) = f(x)
plug in the points (2,1) then solve
Solution
For this case we can conclude that:
f(2) =1
So then we satisfy that:
f(-2) =1
