Astudent is asked to calculate the volume, in milliliters, of 2 cups of oil. there are 225ml per cup. the student calculates the volume as follows:

volume=2cups x 1cup/25ml= 8 cups
list three errors the student made

To calculate the volume, we use the data given above. For this problem we are asked to convert cups to mL.

volume = ( 2 cups) 225 mL / 1 cup = 450 mL

The student's error in converting is that she divide the conversion factor instead of multiplying it, wrote the conversion factor incorrectly and the units of his final answer is wrong.

I believe the opposite of a number would be the negative of that number. Haven't seen it worded like that before though. Five less is minus 5. Three times the sum is 3(x+(-7)). Is would be equals.

x= a number

Equation:
-x - 5 = 3(x + (-7))

If you solve for x:
-x - 5 = 3(x + (-7))
-x-5=3(x-7)
-x-5= (3*x) + (3*-7)
-x-5= 3x-21
Add -x to both sides
-5= 4x-21
Add 21 to both sides
16= 4x
Divide both sides by 4
4= x

Check:
-x - 5 = 3(x + (-7))
-(4)-5= 3((4) + (-7))
-9 = (3*4) + (-21)
-9 = 12 - 21
-9 = -9

Hope this helps! :)