1) Tính nhanh:
a, -987 – 792 + 1034 + 887 – 834 + 792
b, -512 + 899 – 999 – 473 + 412
2) Bỏ ngoặc rồi tính:
a, -( 38 – 59 ) – ( 259 – 188 )
b, ( 319 – 817 ) – ( -817 + 519 )
1) Tính nhanh:
a, -987 – 792 + 1034 + 887 – 834 + 792
b, -512 + 899 – 999 – 473 + 412
2) Bỏ ngoặc rồi tính:
a, -( 38 – 59 ) – ( 259 – 188 )
b, ( 319 – 817 ) – ( -817 + 519 )
`\text{~~Holi~~}`
`1/`
`a. -987-792+1034+887-834+792`
`= -1821+1921`
`= 100`
`b. -512+899-999-473+412`
`= -100-100-473`
`= -673`
`2/`
`a. -(38-59)-(259-188)`
`= -38+59-259+188`
`= (-38+188)+(59-259)`
`= 150-200`
`= -50`
`b. (319-817)-(-817+519)`
`= 319-817+817-519`
`= (319-519)+(-817+817)`
`= -200+0`
`= -200`
1) Tính nhanh:
a)-987-792+1034+887-834+792
=(-987+887)+(1034-834)+(-792+792)
=-100+200+0
=100
b)-512+899-999-473+412
=(-512+412)+(899-999)-473
=-100+(-100)-473
=-200-473
=-673
2) Bỏ ngoặc rồi tính:
a)-(38-59)-(259-188)
=-38+59-259+188
=(59-259)+(-38+188)
=-100+150
=50
b)(319-817)-(-817+519)
=319-817+817-519
=(319-519)+(-817+817)
=-200+0
=-200
HỌC TỐT