a. \(\dfrac{1}{2}-\left(\dfrac{1}{3}+\dfrac{1}{10}\right)=\dfrac{1}{2}-\dfrac{13}{30}=\dfrac{1}{15}\)
b. \(\dfrac{1}{12}-\left(\dfrac{-1}{6}-\dfrac{1}{4}\right)=\dfrac{1}{12}-\left(-\dfrac{5}{12}\right)=\dfrac{6}{12}=\dfrac{1}{2}\)
`a) 1/2 - (1/3 + 1/10)`
`=1/2 - 1/3 -1/10`
`=(1/2 - 1/10 ) -1/3 = (5/10 - 1/10) -1/3`
`=2/5 - 1/3 = 6/15 - 5/15`
`=1/15`
`b) 1/12-(-1/6 -1/4) `
`=1/12 + 1/6 +1/4`
`=1/12 + 2/12 + 3/12`
`=6/12 = 1/2`
`1/2 - (1/3+1/10)`
`=1/2 - (10/30 + 3/30)`
`=1/2 -((10+3)/30)`
`=1/2 -13/30`
`=15/30 -13/30`
`=(15-13)/30`
`=2/30`
`=1/15`
__________________________
`1/12 - (-1/6 - 1/4)`
`=1/12 + 1/6 + 1/4`
`=1/12 + 2/12 + 3/12`
`=(1+2+3)/12`
`=6/12`
`=1/2`