Question

Will give BRAINLIEST for *CORRECT* answer

Answer 1

To prove something by induction you need to verify 2 things
1-the base case,2-it holds for n+1
the base case n=1
10=5(1)(1+1) which is true
it holds for n+1
10+20+30+....+10(n+1)=5(n+1)(n+2)
5n(n+1)+10(n+1)=5(n+1)(n+2)
(5n+10)(n+1)=5(n+1)(n+2)
5(n+2)(n+1)=5(n+1)(n+2) which is true our proof is done.