Question

Rezolva urmatoarele cerinte:
A)afla numarul a daca ab+ac=520 si b+c=52
B)afla numarul a, daca ab-ac=45 si b-c=9
C) afla suma b+c daca ab+ac-70=170 si a=25
D) afla diferenta b-c daca ab-ac -48=2 si a=10.va rog repede

Answer 1

A) ab+ac=520 <=> a×(b+c)=520 <=> a×52=520 => a=520:52 => a=10
B) ab-ac=45 <=> a×(b-c)=45 <=> a×9=45 => a=45:9 => a=5
C) ab+bc-70=170 <=> ab+bc=170+70=240 <=> a×(b+c)=240 => 25×(b+c)=270 => b+c=270:25 => b+c= 10,8
D) ab-ac-48=2 <=> ab-ac=2+48=50 <=> a×(b-c)=50 => 10×(b-c)=50 => b-c=50:10 => b-c=5