Question

Va rog urgent ex 10!dau coronita​

Answer 1

Răspuns:

7a+10b=105

7a=105-10b

7a=5(21-2b)=>7a este divizibil cu 5=>a=5 nr prim

7·5+10b=105

10b=105-35

10b=70=>b=7 nr prim

a=5,b=7

Answer 2

$\it a,\ b\ -\ numere\ prime\ \ \ \ \ (*)\\ \\ 7a+10b=105\ \ \ \ \ (1)\\ \\ 105\in M_5 \stackrel{(1)}{\Longrightarrow} 7a+10b\in M_5 \Rightarrow 7a\in M_5 \stackrel{(*)}{\Longrightarrow}a=5\ \ \ \ \ (2)\\ \\ (1),\ (2) \Rightarrow 35+10b=105|_{-35}\Rightarrow 10b=70 \Rightarrow b=7$

Prin urmare, numerele cerute sunt: a=5,  b=7.