FD
2 tháng 3 2020 lúc 21:33
a) =13- 145 + 49 - 13 -49
= (13- 13) + (49-49) - 145
=-145
b) = 25x8 + (15-18+12-19+10)
=200+0
=200
a)Ta có:
(13-145+49)-(13+49)
=13-145+49-13-49
=145+(13-13)+(49-49)
=145+0+0=145
b)Ta có:
25.23+(15-18)+(12-19+10)
=25.8+15+12+10-18-19
=200+(15+12+10)-(18+19)
=200+37-37
=200+(37-37)
=200+0
=200
vậy thì sẽ bằng 25.22+0=25.4=100
a) ( 13+49) - 145 - (13+49)
= [( 13+49) -(13+49)] - 145
= 0 -145
= -145
b) 25. 8 + 15 - 18 + 12- 19 + 10
=200+(15+12-18-19+10)
=200
Trả lời:
\(a,\)\(\left(13-145+49\right)-\left(13+49\right)\)
\(=13-145+49-13-49\)
\(=\left(13-13\right)-\left(49-49\right)-145\)
\(=0-0-145\)
\(=-145\)
\(b,\)\(25.2^2+\left(15-18\right)+\left(12-19+10\right)\)
\(=25.4+\left(15-18+12-19+10\right)\)
\(=100+0\)
\(=100\)