Question

Tính một cách hợp lí:

a) 10 - 12 - 8; 

b) 4 - (-15) - 5 + 6;

c) 2 - 12 - 4 - 6;

d) -45 - 5 - (-12) + 8.

Answer 1

a, -10

b, 20

c, -20

d, -30

Answer 2

a) 10 – 12 – 8 = 10 – (12 + 8) = 10  - 20 = - 10

b) 4 – (- 15) – 5 + 6 = (4 + 6) – [(-15) + 5)] = 10 – (- 10) = 10 + 10 = 20

c) 2 – 12 – 4 – 6 = (2 – 12) - (4 + 6) = -10 + (- 10) = - 20

d) – 45 – 5 – (- 12) + 8 = - (45 + 5) + (12 + 8) = (- 50) + 20 = - 30

Answer 3

a) 10-12-8=2-12=-10

b) 4-(-15)-5+6=4+15-5+6=10+10=20

c) 2-12-4-6=-10-10=-20

d) -45-5-(-12)+8=-50+12+8=-50+20=-30