I got two tasks which I have some trouble with.
A guy has 1770 dollars to shop food for. One bread costs 31 dollars and a jar of jam costs 21 dollars.
How many loafs of bread and jar's of jam can the guy buy?
I'm suppose to calculate it using Euler Algebra
31x + 21y = 1770
Do I solve this by guessing x,y ?
a) Show that an integer, is congruent 3 mod 4, and which has a prime factor which is congruent modulo with 4.
How do I do that?
b) show that infinit many prime numbers are congruent 3 mod 4.
Sincerely Yours MT
p.s. I'm going to hospital tomorrow for a operation with my heart, so therefore I hope that there is somebody out who could be so kind to help me answer these two questions.