a+b+c=60
[tex] \frac{1}{2}a+3=x; \frac{1}{2}a =x-3;a=2x-6 [/tex]
[tex] \frac{1}{2}b+6=x+1; \frac{1}{2}b=x+1-6; \frac{1}{2}b=x-5;b=2x-10 [/tex]
[tex] \frac{1}{2}c+9=x+2; \frac{1}{2}c=x+2-9; \frac{1}{2}c=x-7;c=2x-14 [/tex]
2x-6+2x-10+2x-14=60
2x+2x+2x=60+6+10+14
6x=90
x=90:6
x=15
[tex] \frac{1}{2}a+3=15; \frac{1}{2}a=12;a=24 [/tex]
[tex] \frac{1}{2}b+6=16; \frac{1}{2}b=10, b=20 [/tex]
[tex] \frac{1}{2}c+9=17; \frac{1}{2}c=8;c=16 [/tex]
cele trei numerele naturale sunt:24, 20 si 16
24+20+16=60
(numerele consecutive obtinute sunt 15,16 si 17)
