Explicație pas cu pas:
a=1/(1+2+3+...+10)
a=1/(11×5)
a=1/55
b=1/(1+2+3...+11)
b=1/(11×5+6)
b=1/61
a) bla puterea -1=
=61/1
=61
b)a/b=
=1/55÷1/61
=1/55×61/1
=61/55
c)-11(a-b)=
=-11(1/55-1/61)
=-11/55+11/61
d)22×(5a-6b)
=22*(5/55-6/61)
=110/55-132/61
