Question

aflati 3 nr naturale consecutive,știind ca media lor aritmetica este 90

Answer 1

$\frac{x+y+z}{3}=90 \\ x+y+z=90 \cdot 3=270 \\ y=x+1 \\ z=y+1=x+2 \\ x+x+1+x+2=270 \\ 3x+3=270 \\ 3x=270-3=267 \\ x=\frac{267}{3} \\ \boxed{\bold{x=89}} \\ y=x+1=89+1 \\ \boxed{\bold{y=90}} \\ z=y+1=90+1 \\ \boxed{\bold{y=91}}$

Answer 2

fie x,x+1,x+2 numerele
⇒x+x+1+x+2/3=90⇔x+x+1+x+2=90*3
⇒3x+3=270
3x=270-3
3x=267
x=267:3
x=89
x+1=89+1=90
x+2=89+2=91
raspuns:89,91,90