Hvordan forenkler du [ frac {2} {9} cdot frac {3} {10} - {- frac {2} {9} div frac {1} {3})] - frac { 2} {5}?

Svar:

#1/3#

Forklaring:

#2/9*3/10-(-2/9-:1/3)-2/5#

=#6/90-(-2/9*3/1)-2/5#

=#6/90+(2/9*3/1)-2/5#

=#6/90+6/9-2/5#

=#6/90+60/90-2/5#

=#66/90-2/5#

=#66/90-36/90#

=#30/90#

=#1/3#