Question

media aritmetica dintre cel mai mare numar si cel mai mic numar natural a pentru care 4a+7e{15,2,27,39}este numarul?

Answer 1

4a+7 = 2 
4a+7= 15 => ca a =2(e nr. mic)
 luam nr maxim adica:39 => a =8(nr mare)
Media aritmetica: (2+8)/2=5

Answer 2

4a+7=2, 4a=2-7, 4a=-5, a=-5/4 care nu e natural
4a+7=15, 4a=15-7, 4a=8, a=8:4, a=2

4a+7=39, 4a=39-7, 4a=32, a=32:4, a=8

$M_{art}= \frac{2+8}{2}=5$