Aball rolls along the floor with a constant velocity of 6m/s. how far will it have gone after 50s

The equation you want to use is v=d/t (velocity= distance divided by time).  You need to rearrange the equation because you are trying to find distance.  Do this by multiplying both sides of the equation by t and isolating d.  Your new equation is d=vt (d=v x t). 
d=6x50=300m

6.97 = 6 97/100

the 6 is a whole number so it goes first and it stands alone

the .97 is in the hundreths place so it will be 97/100

so it is 6 97/100

to convert the mixed fraction into an improper fraction you need to mulitply then add
so denomintoar times whole number then plus 97 so it will be 100*6= 600+97=697
THE DENOMINATOR ALWAYS STAY THE SAME IF YOU ARE CONVERTING INTO AN IMPROPER FRACTION

so improper fraction= 697/100
mixed number= 6 97/100