Question

media aritmetica a numerelor a,b,c,d este 35. Determinati media aritmetica a numerelor a,b,c,d si 25.

Answer 1

$\frac{a+b+c+d}{4} = 35$ => a+b+c+d = 35*4=140
$\frac{140+25}{5} = \frac{165}{5} = 33$

Answer 2

(A+B+C+D):4=35   35X4=140  
 A+B+C+D=140 
(A+B+C+D+25):5=  
=(140+25):5  
=165:5
=33