Fermi
·
Concept Library
·
Courses
·
Books
·
Problems
·
Simulations
·
Math Wiki
·
High School
Fermi
›
Problems
Mathematics
Mathematics
Problem
Find the value of
∑
k
=
1
m
+
2
9
−
∑
k
=
1
m
9
\displaystyle \sum_{k=1}^{m+2} 9 \; - \; \sum_{k=1}^{m} 9
k
=
1
∑
m
+
2
9
−
k
=
1
∑
m
9
for any positive integer
m
m
m
.
Browse the problem library