Question

Stiind că:23× a+77×b=51330 și 77×a+23×b=24170, aflați a+b .​

Answer 1

Răspuns:

755

Explicație pas cu pas:

$\left \{ {{23a+77b=51330} \atop {77a+23b=24170}} \right. \left \{ {{23a+23b+54b=51330} \atop {23a+23b+54a=24170}} \right.  \\Adunam\\2*(23a+23b)+54a+54b=51330+24170\\2*23*(a+b)+54*(a+b)=75500\\46(a+b)+54(a+b)=75500\\100(a+b)=75500\\a+b=75500:100\\a+b=755$