need help with the following problems!

Problem 4)\" Use Mathematical Induction to prove that 5|[11n 1] for all integers n 2 1. [You will lose points if you don't use induction] (Recall that for integers d and m, we say that \"d divides m\Problem 7) (3 points): How many integer solutions are there to the equation 131 +$2+$3 +134 =11 where 11:1 2 2, $2 2 33 x3 2 4, 3:4 2 _2? Problem 9) (2 points): Draw an example of a connected bipartite simple graph with 8 vertices and 9 edges that has an Euler tour. Explain/verify that your example has the desired properties