2. Tính
a) 4 – (-15) – (+15) +17) + 3
b) – (-17) – (+15) + 18 -20
c) -14 + (-13) – (-9) – 5
d) -12 + (+14) – 17 + (-3)
đ) 11 – 15 + 13 – 17 + 8 -4
2. Tính
a) 4 – (-15) – (+15) +17) + 3
b) – (-17) – (+15) + 18 -20
c) -14 + (-13) – (-9) – 5
d) -12 + (+14) – 17 + (-3)
đ) 11 – 15 + 13 – 17 + 8 -4
Đáp án:
a) 4 – (-15) – (+15) + 17 + 3
= 4 + 15 – 15 + 17 + 3
= 4 + 0 + 17 + 3
= 4 + 20
= 24
b) -(-17) – (+15) + 18 – 20
= 17 – 15 + 18 – 20
= (17 + 18) – (15 + 20)
= 35 – 35
= 0
c) -14 + (-13) – 17 + (-3)
= -(14 + 13) – (17 + 3)
= -27 – 30
= -57
d) -12 + (+14) – 17 + (-3)
= -(12 + 17 + 3) + 14
= -32 + 14
= -18
e) 11 – 15 + 13 – 17 + 8 – 4
= (11 + 13 + 8) – (15 + 17 + 4)
= 32 – 36
= -4
Chúc học tốt!!!
`a, 4 – (-15) – (+15) + 17 + 3`
`= 4 + 15 – 15 + 17 + 3`
`= 4 + (15 – 15) + (17 + 3)`
`= 4 + 0 + 20`
`= 4 + 20`
`= 24`
`b, – (-17) – (+15) + 18 – 20`
`= 17 – 15 + 18 – 20`
`= (17 – 15 + 18) – 20`
`= 20 – 20`
`= 0`
`c, -14 + (-13) – (-9) – 5`
`= -14 – 13 + 9 – 5`
`= -27 + 9 – 5`
`= -18 – 5`
`= -23`
`d, -12 + (+14) – 17 + (-3)`
`= -12 + 14 – 17 – 3`
`= 2 – (17 + 3)`
`= 2 – 20`
`= -18`
`đ, 11 – 15 + 13 – 17 + 8 – 4`
`= -4 + 13 – 17 + 8 – 4`
`= 9 – 17 + 8 – 4`
`= -8 + 8 – 4`
`= 0 – 4`
`= -4`