Question

Ajutatima si pe mn cu urmatoarele problema va rogg ; 
PROBLEMA 1; Stiind ca ab+ac= -32 si ca a= -4,calculati b+c.
PROBLEMA 2; Stiind ca xa+xb - xc=288 si ca a+b-c= -9,aflati x.
PROBLEMA 3; Stiind ca (x-3) · a+(x-3)·2b-5c·(x-3)=4850 si ca a+2b-5c=194,aflati x.. VA ROGG DACA SE POATE CAT MAI REPEDE
 

Answer 1

ab+ac=-32
a(b+c)=-32
-4(b+c)=-32
b+c=8

xa+xb-xc=288
x(a+b-c)=288
-9(a+b-c)=288
a+b+c=-32

(x-3)*a + (x-3) *2b-5c*(x-3)=4850
(x-3)(a+2b-5c)=4850
194(x-3)=4850
x-3=25
x=25+3
x=28

Answer 2

ab+ac= -32 si ca a= -4,calculati b+c.
a(b+c)=-32
-4(b+c)=-32
b+c=-32:(-4)
b+c=8
============
xa+xb - xc=288 si ca a+b-c= -9,aflati x.
x(a+b-c)=288
x*(-9)=288
x=288:(-9)
x=-32
=================
Stiind ca (x-3) · a+(x-3)·2b-5c·(x-3)=4850 si ca a+2b-5c=194,aflati x..
xa-3a+2bx-6b-5xc+15c=4850
xa+2xb-5xc-3a-6b+15c=4850
x(a+2b-5c)-3(a+2b-5c)=4850
x*194-3*194=4850
x*194-582=4850
194x=5432
x=28