\(\text{–( –2019 + 2020 ) + (– 2019 ) – ( 1234 – 2020 ) }\)
\(=2019-2020-2019-1234+2020\)
\(=\left(2019-2019\right)+\left(-2020+2020\right)-1234\)
\(=0+0-1234=-1234\)
\(\text{– 25.800 .( – 0,04).1,25.2020}\)
\(=\left(-25\right).\left(-0,04\right).800.1,25.2020\)
\(=1.1000.2020=2020000\)
\(\text{( 5678 – 975 ) – (– 975 + 678 ) + 4000 }\)
\(=5678-975+975-678+4000\)
\(=\left(5678-678\right)+\left(-975+975\right)+4000\)
\(=5000+0+4000=9000\)
\(\text{– 78. (–245 ) + 245. 22}\)
\(=245.\left(78+22\right)\)
\(=245.100=24500\)
\(\text{765.( – 36) – 765. 64 }\)
\(=765.\left[\left(-36\right)-64\right]\)
\(=765.\left(-100\right)=-76500\)
\(\text{5632.121 + 5632 – 5632.22 }\)
\(=5632.\left(121+1-22\right)\)
\(=5632.100=563200\)
chúc bạn học tốt !!!!
