Question

3a+4b=26 stiind ca a si b sunt prime

Answer 1

a,b ∈ N prime
3a+4b=26
4b< 26⇒ b≤6
b prim ∈ {2,3}
b=2 ⇒ 3a+8=26/-8
3a=18/:3
a=6⇒nu merge deoarece nu este prim
b=3 ⇒ 3a+12=26/-12
3a=14/:3
a=4,(6); nu merge deoarece ∉ N
3a<26 ⇒a≤8
a prim ∈ {2,3,5,7}
a=2 ⇒ 6+4b=26/-6
4b=20/:4
b=5; MERGE
a=3 ⇒ 9+4b=26/-9
4b=17/:4
b=NU MERGE
a=5 ⇒15+4b=26/-15
4b=11/:4
b=NU MERGE
a=7 ⇒ 21+4b=26/-21
4b=5/:4
b=NU MERGE

RASPUNS: a=2; b=5