Question 986919
{{{sum(I(I+1)(I+2),I=1,5)=1(1+1)(1+2)+2(2+1)(2+2)+3(3+1)(3+2)+4(4+1)(4+2)+5(5+1)(5+2)}}}
{{{sum(I(I+1)(I+2),I=1,5)=1(2)(3)+2(3)(4)+3(4)(5)+4(5)(6)+5(6)(7)}}}
Use a calculator to finish.