The digit with the greatest value 6789

The digit with the greatest value is 6 because it is in the thousands place.

6*1000=6000
7*100=700
8*10=80
9*1=9

Of these values, 6000 is the largest due to its place value.

First step is to get rid of the square root. remember that a square root is the same as raising to the (1/2) power. see below: multiply exponents per exponent rules to get: remember you subtract exponents from the denominator and add exponents in the numerator so: simplify further: so a is the correct choice. if you don't understand this google exponent rules and it will you understand. look at the image results.