27.75 + 25.27 - 2.3.5²

= 27.(75 + 25) - (2.5).(3.5)

= 27.100 - 10.15

= 2700 - 150

= 2550

35 - 5 x (-2) : 6

= 35 - (5 x -2) :6

= 35 - (-10) : 6

= 35 - \(\left(-\dfrac{5}{3}\right)\)

= 35 + \(\dfrac{5}{3}\)

= \(\dfrac{105}{3}\) + \(\dfrac{5}{3}\)

= \(\dfrac{110}{3}\)