Step-by-step explanation:
[tex]\bold{METHOD\ 1}\\\\3\dfrac{1}{8}=2+1\dfrac{1}{8}=2+\dfrac{9}{8}=2\dfrac{9}{8}\\\\3\dfrac{1}{8}-1\dfrac{7}{8}=2\dfrac{9}{8}-1\dfrac{7}{8}=(2-1)+\dfrac{9-7}{8}=1+\dfrac{2}{8}=1\dfrac{2:2}{8:2}=1\dfrac{1}{4}[/tex]
[tex]\bold{METHOD\ 2}\\\\3\dfrac{1}{8}-1\dfrac{7}{8}=(3-1)+\dfrac{1-7}{8}=2+\dfrac{-6}{8}=2-\dfrac{6}{8}=1\dfrac{8}{8}-\dfrac{6}{8}=1\dfrac{8-6}{8}=1\dfrac{2}{8}=1\dfrac{1}{4}[/tex]
[tex]\bold{METHOD\ 3}\\\\\text{convert to the decimal:}\\\\3\dfrac{1}{8}=3+(1:8)=3+0.125=3.125\\\\1\dfrac{7}{8}=1+(7:8)=1+0.875=1.875\\\\3\dfrac{1}{8}-1\dfrac{7}{8}=3.125-1.875=1.25=1\dfrac{25}{100}=1\dfrac{25:25}{100:25}=1\dfrac{1}{4}[/tex]
