\(0,875-0,15+0,25-0,85-0,125+0,6+0,4+0,123\)

\(=\left(0,875-0,125+0,25\right)-\left(0,85+0,15\right)+\left(0,6+0,4\right)+0,123\)

\(=1-1+1+0,123\)

\(=1+0,123=1,123\)

\(0,123.5+0,123:0,25+0,123\)
\(=0,123.5+0.123.4+0,123.1\)
\(=0,123.\left(5+4+1\right)\)
\(=0,123.10=1,23\)
. là dấu nhân.

\(=0,123\times5+0,123\times4+0,123\\ =0,123\left(5+4+1\right)\\ =0,123\times10\\ =1,23\)

\(0,123\) x \(5+0,123:0,25+0,123\)

\(=0,123\) x \(5+0,123\) x \(4+0,123\)

\(=0,123\) x \(\left(5+4+1\right)\)

\(=0,123\) x \(10\)

\(=1,23\)

0,123 x 5 + 0,123 : 0,25 + 0,123       

= 0,123 x 5 + 0,123 x 4 + 0,123       

= 0,123 x ( 5 + 4 + 1 )

= 0,123 x 10

= 1,23

a: \(0,123\cdot450+1,23\cdot55\)

\(=1,23\cdot45+1,23\cdot55\)

\(=1,23\left(45+55\right)=1,23\cdot100=123\)

b: \(0,234\cdot3700+23,4\cdot62\cdot26\cdot9\)

\(=23,4\cdot37+23,4\cdot62\cdot26\cdot9\)

\(=23,4\left(37+62\cdot26\cdot9\right)=340353\)

0,123 x 5 + 0,123 x 4 + 0,123

= 0,123 x (5+4+1)

=0,123 x 10

= 1,23

0,123 x 5 + 0,123 x 4 + 0,123

= 0,123 x (5+4+1)

=0,123 x 10

= 1,23

a: Sửa đề:\(4,89\cdot4,5+4,89\cdot4,5+4,89\)

\(=4,89\cdot\left(4,5+4,5+1\right)\)

\(=4,89\cdot10=48,9\)

b: \(0,123\cdot7800+1,23\cdot220\)

\(=1,23\cdot780+1,23\cdot220\)

\(=1,23\left(780+220\right)\)

\(=1,23\cdot1000=1230\)

c: \(0,4\cdot0,45\cdot2,5\)

\(=0,4\cdot2,5\cdot0,45\)

\(=1\cdot0,45=0,45\)

d: \(0,2\cdot5,55\cdot50\)

\(=0,2\cdot50\cdot5,55\)

\(=5,55\cdot10=55,5\)

a: x*2,3-4,6=2,3

=>x*2,3=6,9

=>x=3

b: =0,123(5+4+1)

=0,123*10

=1,23

a) = 367 + 125 - 367 + 125

    = (367 - 367) + (125+125) 

    = 0 + 250

    = 250

b) = 29 - 614 + 386 + 71

= ( 29 + 71 ) - ( 614 + 386 )

= 100 - 1000

= - 900