Determine all integer solutions of the equation
Determine all the integer solutions for the equation
Solve the equation with integers
Prove that out of
Prove that every number
a) the sum of the numbers of the previous right diagonal, starting from the leftmost number up until the one to the right above the number
b) the sum of the numbers of the previous left diagonal, starting from the leftmost number to the one to left of the number which is above
Prove that there exists a graph with 2n vertices whose degrees are
a) they have 10 vertices, the degree of each of which is equal to 9?
b) they have 8 vertices, the degree of each of which is equal to 3?
c) are they connected, without cycles and contain 6 edges?
In a graph, all the vertices have degree of 3. Prove that there is a cycle in it.
There are seven lakes in some country, connected by ten non-overlapping canals, and each lake can be reached from any other. How many islands are there in this country?