a)

349 + 602 + 651 + 398

= (349 + 651 ) + (602 + 398)

= 1000 + 1000

= 2000

b) 

3145 - 246 + 2347 - 145 + 4246 - 347

= (3145 - 145) + (4246 - 246) + (2347 - 347)

= 3000 + 4000 + 2000

= 7000 + 2000

= 9000

\(349+602+651+398\)

\(=\left(349+651\right)+\left(602+398\right)\)

\(=1000+1000\)

\(=2000\)

_____

\(3145-246+2347-145+4246-347\)

\(=\left(3145-145\right)+\left(2347-247\right)+\left(4246-246\right)\)

\(=3000+2000+4000\)

\(=9000\)

=145x(1+2+1)=145x4=580

145+145X145+145= 145x4=580

(a \(\times\) 1 - a:1):(347 - 252 + 4x 8)

= 0 : (347 - 252 + 4 x 8)

= 0

ủng hộ mk nha

1784:x=4

x=1784:4

x=446

X;8=1039

x=1039x8

x=8312

x+347=145x6

x+137=870

x=870-137

x=733

917-x=984:2

917-x=492

x=917-492

x=425

a)

=347x6+347x3+347x1

=347x(6+3+1)

=347x10

=3470

b)

=2013x3+2013x7

=2013x(3+7)

=2013x10

=20130

a)

= 347 x 6 + 347 x 3 + 347 x 1

= 347 x ( 6 + 3 + 1 )

= 347 x 10

=3 470

b)

=2 013 x 3 + 2 013 x 7

=2 013 x ( 3 + 7 )

=2 013 x 10

=20 130

`Thảo`

a) \(33\times4+5\times33+33\times3+33-99=33\times4+5\times33+33\times3+33\times1-33\times3\)

\(=33\times\left(4+5+3+1-3\right)=33\times10=330\)

b) \(256+347+453-147-56-253=\left(256-56\right)+\left(347-147\right)+\left(453-253\right)\)

\(=200+200+200=600\)

a) 125.3+125.125.6

=125.3+125.750

=125.(3+750)

=125.753

=94125

b) (245.99+245)-(145.101-145)

=(245.(99+1))-(145.(101-1))

=245.100-145.100

=(245-145).100

=100.100

=10000

c) 154.(28+52)-45.(26+54)

=154.80-45.80

=(154-45).80

=109.80

=8720

a) 125x3+125+125x6

=125x(3+1+6)

=125x10

=1250

b) (245x99+245)-(145x101-145)

=(245x99+245)-(145x100)

=(245x100)-14500

=24500-14500

10000

c) 154x80-45x80

=80x(145-45)

=80x100

=8000

TL

(12x6-12x4-12x2)x(347+125)

=[12x(6-4-2)]x472

=(12x0)x472

=0x472

=0

HT

\(=0\)

HT

 365 + 123 + 347

= (123 + 347 ) + 365

= 470 + 365

= 835

tk va kb với mk nha 

mk het luot roi

thật đó

365 + 123 + 347 = 835

kb nha