Answer: 1 + 1 = 2
Step-by-step explanation:because that's how we've defined it, in the same way that the word "cat" refers to small, furry, feline creatures because that's how we've defined it.
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: By the 8th week.
Step-by-step explanation:
Let the time that matteo and luca have the same amount of money be represented by x.
The information given in the question can be formed into an equation as:
400 - 10x = 200 + 15x
Collect like terms
400 - 200 = 15x + 10x
200 = 25x
x = 200/25
x = 8
Matteo and Luca will have the same amount of money by the 8th week.
Answer: By cross multiplication.
Step-by-step explanation: Given product is 3 × 292.
We know that after simple multiplication, we get 3 × 292 = 876.
Now, to check division with multiplication, either we need to divide 876 by 3 to get the answer 292,
or
we need to divide 876 by 292 to get the answer 3.
We will do that as follows -

Thus, doing cross-multiplication, we arrive at our conclusion.
Answer:
(-b) is the answer.
Step-by-step explanation:
2(a-b)-(2a-b)
=2a-2b-2a+b (opening the brackets)
= -b
Hope this helps you buddy. Have a nice day^_^.
If you have doubt then you can ask in comments. I will surely answer.