Question

Вычислите рационально
4,9*6,8+5,1*1,2+5,1*6,8+4,9*1,2

Answer 1

=6.8·(4.9+5.1)+1.2·(5.1+4.9)=6.8·10+1.2·10=10·(6.8+1.2)=10·8=80