What is the smallest positive integer n such that the fourth root of 98n is an integer?
The prime factorization of 98 is 72×2.
Because we are taking the fourth root, everything must be raised to a power of a multiple of 4, (4, 8, 12, etc.)
This means that the smallest value of n that works is 72×23=392
Thanks for the feedback!!
Note that because all the bases in the term 74×24 are raised to the 4th power, the 4th root of this is an integer.
So, we basically have: 74×247x×2y=72×21
Start with 747x . We want this to equal 72.
Recall that when you are dividing exponents with the same base, you subtract the exponents (34÷32=34−2=32).
Applying that here, we have 74÷7x=72, thus x=2. (74÷72=74−2=72)
Now, doing the same thing to 242y. We want this to equal 21, so y=3. (24÷23=24−3=21).
So, the answer we are looking for is 72×23=392
Hope this helps!