Mathematician

If this is a linear equation, you're probably trying to isolate y. To do that, you have all "y" on one side and no y's on the other side:

3x + 1/5y = 7

Subtract 3x from both sides:

3x + 1/5y = 7

3x - 3x + 1/5y = 7 - 3x

0 + 1/5y = 7 - 3x

1/5y = 7 - 3x

Multiply both sides by 5, to cancle the 1/5 coefficient of y:

1/5y = 7 - 3x

5(1/5)y = 5(7) - 5(3)x

y = 35 - 15x

You can also switch the x and the constant term, for the form 'y = mx + b':

y = -15x + 35

Add the digits vertically from right to left:

0 + .5 = .5:

 28

+ 1.5

   .5

8 + 1 = 9:

 28

+ 1.5

  9.5

2 + 0 = 2:

 28

+ 1.5

 29.5

------

8+0 = 8:

 28

+10

  8

2 + 1 = 3:

 28

+10

 28

So to express that numerically would be:

-4/5 / 4

The easiest way to divide fractions is to multiply by the recipricol of the number which is being divided.

The recipricol is simply the fraction flipped upside down.

So for 4 (= 4/1), the recipricol is simply 1/4:

-4/5 * 1/4

Then the top and bottom of both fractions can be performed:

(-4*1) / (5*4)

The fours on the top and bottom can cancel out, leaving us with:

-1/5.

9 1/2% = 9.5%

To do this problem, turn the percentage into a decimal. This is done by dividing the percentage by 100 (since 100% is 1 in decimal notation).

So:

9.5% = 0.095

0.095 * 50 = 4.75

I'm not quite sure what you're referring to.
 

The only possible multiplication in the midpoint formula is perhaps multiplication of the two x's and two y's respectively by 1/2.

If that's what you're referring to, it's important because it averages the two numbers.

"Rate of change" is really only relevant when looking at change over a period of time.

You can find the amount of change given those values: it's just the difference between them.

0.5 / -5 * 50

0.5 / -5 is the same thing as -5/50 (multiplying by -5/50)

-5/50 * 50

-5*50/50

50's on the top and bottom cancel out, leaving us with -5.

-5*50/50 = -5

Given the description, it appears to be an GCF problem.

So that means we have to find the greatest common factor common to all 3 volumes:

I'll start by listing factors of the largest number, 1000:

1000

1 * 1000

2 * 500 -> That matches 500, so it's a factor of 500, but it's too large to be a factor of 250

4 * 250 -> Matches 250, so it's a factor of 250.

Having found a factor for both 1000 and 250, we can now check if 500 also has that factor:

500

1 * 500

2 * 250

If I interpreted the problem correctly, 250mL should be the answer.