Solution 3.1:4c

From Förberedande kurs i matematik 1

Each term in the expression can be simplified by breaking down the number under the root sign into its factors,

50201880=510=552=252=210=225=225=29=233=232=810=(24)(25)=(222)(25)=245

and then taking the squares out from under the root sign,

50201880=252=52=225=25=232=32=245=225=45.

All together, we get

50+420−318−280=52+425−332−245=52+85−92−85=(5−9)2+(8−8)5=−42.