b= [tex]\sqrt{36/25}[/tex]+√0,64+√1,44+2×√3,61
b=6/5+0,8+1,2+2×1,9
b=6/5+8/10+ 12/10+3,8
b=12/10+8/10+ 12/10+38/10
b=70/10
b=7 care ∈ N
