Tính hợp lý :
a) ( -75 ) + ( -325 ) + | -45 | - ( - 125 )
b) 62 + | 128 | - | - 155 | - | 70 |
c) 815 + [ 95 + ( -815 ) + -45 ) ]
d ) 5 + ( -7 ) + 9 + ( -11 ) + ... + 25 + ( -27 )
e ) 34 + 35 + 36 + 37 - 24 - 25 - 26 - 27
g) ( -100 ) + 112 + ( -114 ) + ... + ( - 198 ) + 200
GIÚP MÌNH VỚI CÁC BẠN ƠI HUHU !!!!
a) \(-75+\left(-325\right)+\left|-45\right|-\left(-125\right)\)
\(=-75-325+45+125\)
\(=\left(45+125\right)-\left(75+325\right)\)
\(=170-400\)
\(=-230\)
b) \(62+\left|128\right|-\left|-155\right|-\left|70\right|\)
\(=62+128-155-70\)
\(\Leftrightarrow190-225\)
\(=-35\)
c) \(815+\left[95+\left(-815\right)+\left(-45\right)\right]\)
\(=815+95-815-45\)
\(=\left(815-815\right)+\left(95-45\right)\)
\(=0+50\)
\(=50\)
d) \(5+\left(-7\right)+9+\left(-11\right)+...+25+\left(-27\right)\)
\(=\left(5-7\right)+\left(9-11\right)+...+\left(25-27\right)\)
\(=-2-2-...-2\)
\(=-2.11\)
\(=-22\)
e) \(34+35+36+37-24-25-26-27\)
\(=\left(34-24\right)+\left(35-25\right)+\left(36-26\right)+\left(37-27\right)\)
\(=10+10+10+10\)
\(=40\)