[m]\sqrt{(a-4)^2}=|a-4|[/m]
[m]\sqrt{(a-10)^2}=|a-10|[/m]
[m]\sqrt{(a-4)^2}+\sqrt{(a-10)^2}=|a-4|+|a-10|[/m]
Так как
[m] 4 ≤ a ≤ 10[/m]
[m]|a-4|=a-4[/m]
[m]|a-10|=-(a-10)=10-a[/m]
[m]\sqrt{(a-4)^2}+\sqrt{(a-10)^2}=|a-4|+|a-10|=a-4+10-a=6[/m]
Ответ: 6