Question

Bỏ dấu ngoặc rồi tính các tổng sau

a) (−28)+(−35)−92+(−82) b) 15−(−38)+(−55)−47

Answer 1

a) (-28) + (-35) – 92 + (-82) = -28 – 35 – 92 – 82 

= - (28 + 35 + 92 + 82) = - [(28 + 82) + (35 + 92)]

= - (110 + 127) = - 237.

b) 15 – (-38) + (-55) – (+47) = 15 + 38 – 55 – 47

= 53 – 55 – 47 = - (55 – 53) – 47

= - 2 – 47 = - (2 + 47) = - 49

Answer 2

a) (-28) + (-35) – 92 + (-82) = -28 – 35 – 92 – 82 

= - (28 + 35 + 92 + 82) = - [(28 + 82) + (35 + 92)]

= - (110 + 127) = - 237.

b) 15 – (-38) + (-55) – (+47) = 15 + 38 – 55 – 47

= 53 – 55 – 47 = - (55 – 53) – 47

= - 2 – 47 = - (2 + 47) = - 49

Answer 3

a,-237

b,-49