a) 24 – (-136) – (-70) + 15 + (-115) b) 12 + 22 + (-20) + (-153) + 8

0 bình luận về “a) 24 – (-136) – (-70) + 15 + (-115) b) 12 + 22 + (-20) + (-153) + 8”

1. `a ) 24 – ( – 136 ) – ( – 70 ) + 15 + ( – 115 )`

   `= [ ( 24 – ( – 136 ) – ( – 70 ) ] + [ 15 + ( – 115 ) ]`

   `= [ 160 – ( – 70 ) ] + ( – 100 )`

   `=  230 + ( – 100 )`

   `=  130`

   `b ) 12 + 22 + ( – 20 ) + ( – 153 ) + 8`

   `= [ 22 + ( – 20 ) + 8 ] + [ ( – 153 ) + 12 ]`

   `= [ 2 + 8 ] + ( – 141 )`

   `=  10 + ( – 141 )`

   `=   – 131 `

    

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2. a) $24 – (-136) – (-70) + 15 + (-115)$

   $=(24+136)+70+(15-115)$

   $=160+70-100$

   $=230-100$

   $=130$

   b) $12 + 22 + (-20) + (-153) + 8$

   $=[12+8+(-20)]+(22-153)$

   $=0+(-131)$

   $=-131$

    

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