Question

3. tính nhanh:

1) -(-8) - 9 + 10 + (-14) + (+12)

2) 8 - 37 + 70 - 8 + 37 - 70 + 10

Answer 1

1: =8-9+10-14+12

=-1+10-14+12

=9-14+12

=-5+12=7

2: =(8-8)+(-37+37)+(70-70)+10=10

Answer 2

\( -(-8) - 9 + 10 + (-14) + (+12)\)

\(=8-9+10-14+12\)

\(=-1+10-14+12\)

\(=9-14+12\)

\(=-5+12 =7\)

\(-----------\)

\(2) 8 - 37 + 70 - 8 + 37 - 70 + 10\)

\(=(8-8)+(37-37)+(70-70)+10\)

\(=0+0+0+10 =10\)

\(\text{#Hàn Thiên Vy}\)

Answer 3

\( -(-8) - 9 + 10 + (-14) + (+12)\)

` = 8 - 9 + 10 - 14 + 12`

` = ( 8 + 12) - 9 + 10  -14`

` = 20 - 9 + 10 - 14

`= 11 +10 - 14`

`= 21 - 14`

`=7`

______________________

`8 - 37 + 70 - 8 + 37 - 70 + 10`

`  = ( 8-  8) + ( -37 + 37) + (70 -70) +10`

` = 0 + 0 + 0 +10`

` = 10`

Answer 4

1) - ( - 8 )   - 9 + 10  + ( - 14 ) + ( + 12 )

= 8 - 9 + 10 + ( - 14 ) + ( + 12 )

= ( - 1 ) + 10 + ( - 14 ) + ( + 12 )

= 9 + ( - 14 ) + ( + 12 )

= ( - 5 ) + 12

= 7

2) 8 - 37 + 70 - 8 + 37 - 70 + 10

= ( 8 - 8 ) + ( 37 - 37 ) + ( 70 - 70 ) + 10

= 0 + 0 + 0 + 10

= 10

Answer 5

1) \(-\left(-8\right)-9+10+\left(-14\right)+\left(+12\right)\)

\(=\left(8+12+10\right)+\left[-9+\left(-14\right)\right]\)

\(=30+\left(-23\right)\)

\(=7\)

2) \(8-37+70-8+37-70+10\)

\(=\left(8-8\right)+\left(-37+37\right)+\left(70-70\right)+10\)

\(=0+0+0+10\)

\(=10\)