So there is this chart my teacher showed me to help find the answers to your questions I will send a picture but here are the answers
30km is 18.642m
44,000in is 111760cm
21ft is 6.401m
0.75m I’m not for sure sorry but
133yards is 121615.2mm
I hope that helps sorry I did not understand the one question 0.75m
The maximum number of turning points in a cubic function is 2.
In this case,

The discriminant is

, which means the derivative has no real roots. This means there are no critical points and thus no turning points/relative extrema.
The common denominator would be 6. Since, the least common multiple of 3 and 6 is 6.
3:
3, 6, 9
6:
6, 12, 18
Least common multiple is 6
If you do 27-12 (which is 15) you add 15 to 13 and 20