Question

tính hợp lý nếu có thể

a) 36 - 44 + 76 - 89- 56

b) ( 342 - 567) - [ 642 - ( 767 - 458 ) ]

c) 1892 - [ 892 + ( - 852 + 300 ) + 852

d) ( 472 - 281 - 513 ) - ( 372 - 181 + 487)

e) ( 912 - 1268 ) - [ 812 - ( 1368 - 100 )]

Answer 1

Lời giải:
a. $=(36+76)-89-(44+56)$

$=112-89-100=12-89=-(89-12)=-77$
b. $=342-567-642+767-458$

$=(342-642)+(767-567)-458=-300+200-458=-100-458=-(100+458)=-558$

c. $=1892-892+852-300-852$

$=(1892-892)+(852-852)-300=1000+0-300=700$

d.

$=472-281-513-372+181-487$

$=(472-372)-(281-181)-(513+487)$

$=100-100-1000=-1000$

e.

$=912-1268-812+1368-100$

$=(912-812)+(1368-1268)-100=100+100-100=100$