a)41²-81-11+11²=1681-82-11+121=1709
b)58²-22²/49²-31²=(58-22)(58+22)/(49-31)(49+31)=
=36*80/18*80=2880/1440=2
a)41²-81-11+11²=1681-82-11+121=1709
b)58²-22²/49²-31²=(58-22)(58+22)/(49-31)(49+31)=
=36*80/18*80=2880/1440=2