a) -209 + (-21 + 75 2009) b) (-2015) – (-55 – 2015) c) (2014 -75) – 2014 d) -37 + 54 + (-70) + (-163) + 246
a) -209 + (-21 + 75 2009) b) (-2015) – (-55 – 2015) c) (2014 -75) – 2014 d) -37 + 54 + (-70) + (-163) + 246
By Reese
By Reese
a) -209 + (-21 + 75 2009) b) (-2015) – (-55 – 2015) c) (2014 -75) – 2014 d) -37 + 54 + (-70) + (-163) + 246
-209 + (-21+75 2009)=-209+[+(75 2009-21)]
=-209+75 1988
=+(75 1988-209)
=+1779=1779
Đáp án:
Giải thích các bước giải:
a, -209+(-21+75+2009)
=(-209 – 21 ) +75 +2009
= -230 + 75+ 2009
= -155+2009
=1854
b) (-2015) – (-55 – 2015)
=2015 + 55 + 2015
= ( 2015 – 2015 ) + (55)
= 55
c) (2014 -75) – 2014
=(2014 – 2014 ) – 75
= -75
d) -37 + 54 + (-70) + (-163) + 246
=37 + 54 – 70 -163 + 246
= ( -37 – 163 ) + ( 246 + 54 ) – 70
= -200 + 300 – 70
= 30