Bài 1: Tính(hợp lý nếu có thể)
a, \(21.76+50.21-21.26\)
\(=21\left(76+50-26\right)\)
\(=21.100\)
\(=2100\)
b, \(24.74+34.25+74\)
\(=74\left(24+1\right)+34.25\)
\(=74.25+34.25\)
\(=25\left(74+34\right)\)
\(=25.108\)
\(=2700\)
c, \(93.61+68.8-61\)
\(=61\left(93-1\right)+68.8\)
\(=61.92+544\)
\(=5612+544\)
\(=6156\)
d, \(13.75+25.13-140\)
\(=13\left(75+25\right)-140\)
\(=13.100-140\)
\(=1300-140\)
\(=1160\)
Bài 2: Tính.
a, \(2018-18:3^2\)
\(=2018-18:9\)
\(=2018-2\)
\(=2016\)
b, \(2.7^2+2019^0-81:3^3\)
\(=2.49+1-81:27\)
\(=98+1-3\)
\(=96\)
Bài 1:
\(21\cdot76+50\cdot21-21\cdot26\\ =21\left(76+50-26\right)\\ =21\cdot100\\ =2100\)
\(34\cdot74+34\cdot25+74\\ =34\left(74+25\right)+74\\ =34\cdot99+74\\ =3366+74\\ =3440\)
\(93\cdot61+68\cdot8-61\\ =61\left(93-1\right)+544\\ =61\cdot92+544\\ =5612+544\\ =6156\)
\(13\cdot75+25\cdot13-140\\ =13\left(75+13\right)-140\\ =13\cdot88-140\\ =1144-140\\ =1004\)
Bài 2:
\(2018-18:3^2\\ =2018-18:9\\ =2018-2\\ =2016\)
\(2\cdot7^2+2019^0-81:3^3\\ =2\cdot49+1-81:27\\ =98+1-3\\ =99-3\\ =96\)
a, \(21.76+50.21-21.26\)
\(=21\left(76+50-26\right)\)
\(=24.100\)
\(=2400\)
b, \(34.74+34.25+74\)
\(=34\left(74+25\right)+74\)
\(=34.99+74\)
\(=3366+74\)
\(=3440\)
c, \(93.61+68.8-61\)
\(=61\left(93+1\right)+68.8\)
\(=5734+544\)
\(=6278\)
d, \(13.75+25.13-140\)
\(=13\left(75+25\right)-140\)
\(=13.100-140\)
\(=1300-140\)
\(=1160\)