If this is what you mean..?
In order to do this you would work backward from the answer.
You have x = 25 and ant to include and addition. As we are working backwards, we use the opposite operation to addition - subtraction. We'll make it an easy number so we will subtract 15 to get to 10.
So far it looks like 10 = 15 + x
Now, to include a division, we want to do the opposite again, multiplication. Pick any number to multiply 10 by - for this example we'll choose 7.
7 x 10 = 70
Now we can write out the equation -
70/7 + 15 = x
No brackets are required as Division comes before addition in BIDMAS.
An alternate choice would be to have x the other side of the '='
To do this, multiply x by a number of choice (for example 3) to make the divison section of the equation. This makes 75. This can be written as a fraction. 75/x = 3
Next, for the addition, whatever happens on one side, the exact same happens on the other. Pick any number to add on (e.g. 5) and re-write the equation.
75/x + 5 = 8
Sorry if this doesn't make perfect sense
Answer:
sure I'll try to help you oh math
The slope is 1/3 because in order to get from point (3,1) to (6,2) you need to rise 1 and go over 3
To solve this problem you must apply the proccedure shown below:
1. You have that
varies jointly as
and
and inversely as the product of
and
. Therefore, you can write the following equation, where
is the constant of proportionality:

2. Now, you must solve for the constant of proportionality, as following:

3. Susbtiute values:


4. Substitute the value of the constant of proportionality into the equation:

The answer is: 
How many red ones were in the bag?