Question

Media aritmetica a numerelor 71,x si 101 este 86.Determinati numarul x.

Answer 1

(71+x+101):3=86
71+x+101=86*3
71+x+101=258
71+x=258-101
71+x=157
x=157-71
x=86

Answer 2

$M _{a} = \frac{71+x+101}{3} =86 \\ 71+x+101=86*3 \\ x+172=258 \\ x=258-172 \\ x=86$