Question

which of the following statements is (are) true for all postitive intergers 1) 2+2^2+2^3+....+2n=2n+1-2 2) 1+3+5+...+n=n^3

Answer 1

1) i think there needs to be exponents to understand it correctly?
Is this correct?
\[2+2^2+2^3+\cdots+2^n=2^{n+1}-2\]

2)as written the formula doesnt make sense, should it be this?
\[1+3+5+\cdots+(2n-1)=n^3\]The reason for the 2n-1 is because you only want odd numbers.

Answer 2

ohh i see cool thanks man :)