$\#phnn$
`a)15\frac{1}{4}:(-2/3)+(-1/2)+4\frac{1}{4}:(-2/3)`
`=61/4.(-3/2)+(-1/2)+\frac{17}{4}.(-3/2)`
`=(-3/2).(61/4+17/4)+(-1/2)`
`=(-3/2). 78/4+(-1/2)`
`=(-3/2). 39/2+(-1/2)`
`=-117/4+(-1/2)`
`=-117/4+(-2/4)`
`=-119/4.`
`b)1/3-2.(-1/2)^3+\sqrt{49/36}`
`=1/3-2.(-1/8)+7/6`
`=1/3-(-1/4)+7/6`
`=1/3+1/4+7/6`
`=4/12+3/12+14/12`
`=21/12`
`=7/4.`
