\(27.62+27.38=27.\left(62+38\right)=27.100=2700\)
a/
= 27 x ( 62 + 38 )
= 27 x 100
= 2700
b/
= 49 x ( 33 + 67 )
= 49 x 100
= 4900
f/
= 49 x 50 + 13 x 49 + 49 x 1
= 49 x ( 50 + 49 + 1 )
= 49 x 100
= 4900
h/
= ( 125 + 375 ) + ( 70 + 230 )
= 500 + 300
= 800
mình xin lỗi vì có 4 câu mình ko làm được
c) 35.11 + 65.18 + 35.13 + 65.6
= 35.(11 +13) + 65.(18 + 6)
= 35.24 + 65.24
= 24.(35 + 65)
= 24.100
=2400
mình cảm ơn nhiều
\(7^2.33+7^2.67=7^2.\left(33+67\right)=7^2.100=49.100=4900\)
d) \(490-\left\{\left[\left(128+22\right):3.2^2\right]-7\right\}\)
\(=490-\left\{\left[150:3.4\right]-7\right\}\)
\(=490-\left\{\left[50.4\right]-7\right\}\)
\(=490-\left\{200-7\right\}\)
\(=490-193\)
\(=297\)
