The reason fractions need a common denominator before adding or subtracting is so that the numbers of pieces you are adding/subtracting are all the same size. Note that the numerator of a fraction just tells you how many pieces you have of that size.
899/7.....if u plug this into a calculator u will get 128.(and a bunch of decimal numbers).....but u have the whole number 128....so 128 x 7 = 896 + 3 = 899
so the answer to this problem is basically : 899/7 = 128 remainder 3
Answer:
12
Step-by-step explanation:
12/2=6
Tell me if it works
Answer:

Step-by-step explanation:
Step 1: Simplify square roots
√72 = 6√2
√50 = 5√2
So, 
Step 2: Cancel like terms

Step 3: Rewrite
And we should get our answer!