Fie x,y,z numerele.
x+y+z=220
2x=y-2=z+7 = a => x= [tex] \frac{a}{2} [/tex] ; y=a+2 si z=a-7.
x+y+z=220 <=> [tex] \frac{a}{2} [/tex] + a+2+ a-7 =220 => [tex] \frac{a}{2} [/tex] +2a =225 <=> [tex] \frac{a}{2} + \frac{4a}{2} =225[/tex] <=> [tex] \frac{5a}{2} =225 => a= \frac{225*2}{5} = 90[/tex]
x=[tex] \frac{a}{2} =45[/tex]
y=a+2=92
z=a-7=83
