a) (39 - 2689) + 2689

= 39 + (2689 - 2689)

= 39 + 0

= 39

__

b) - (12 345 - 999) = - (12 345 - 1000+1)

- 12 345 + 12345 + 999 -1000+ 1 = 0

0=0

----

c) (-1312) - (1998 - 1312) 

= (1312 - 1312) - 1998

= 0 - 1998 = -1998

d) (-6955) - 33 - 45 -  (-133)

= -(6955+45) - (33 - 133) 

= -7000 - (-100)

= -7000 + 100 = -6900

e) (-21) - 23 - [16 - (-18) - 18 - 16] + 2144

= -21 - 23 - 16 - 18 + 18 + 16 + 2144

= (16 - 16) + (18 - 18) + (2144 - 21 - 23)

= 0 + 0 + 2100

= 2100

g) (-2020) - 2018 - 2016 - ...-2008

= - [(2020+ 2008): 2 x 7]

= -[(4028): 2 x 7]

= -[2014 x 7]

= - 14098

a: \(145+43+\left(-145\right)+57\)

\(=\left(145-145\right)+\left(43+57\right)\)

=0+100

=100

b: \(\left(-123\right)+101+\left(-777\right)+99\)

\(=\left(-123-777\right)+\left(101+99\right)\)

=-900+200

=-700

c: \(\left(-8955\right)+33+\left(-45\right)+\left(-133\right)\)

\(=\left(-8955-45\right)+\left(33-133\right)\)

\(=\left(-9000\right)+\left(-100\right)=-9100\)

d: \(\left(-2\right)+\left(-4\right)+\left(-6\right)+\left(-8\right)+\left(-10\right)+8+10+12\)

\(=\left(12-2\right)+\left(-4-6\right)+\left(-8+8\right)+\left(-10+10\right)\)

=10-10+0+0

=0

1883 

mk ko trình bày đâu nha

=1824

cậu kết bạn với mình nha

1874 nha k

=133.50-33.153

=6650-5049

=1601

133 ( 30 + 20 ) - 33 ( 133 + 20 )

= 133 * 30 + 133 * 20 - ( 33 * 133 + 33 * 20 )

= 133 * 30 + 133 * 20 - 33 * 133 - 33 * 20 

= 133 * 30 - 33 * 133 + 133 * 20 - 33 * 20

= 133 ( 33 - 30 ) + 20 * ( 133 - 33 )

= 133 * 3 + 20 * 100

= 399 + 2000

= 2399

\(135.\left(33+20\right)-33.\left(133+20\right)\)

\(=135.53-33.153\)

\(=7155-5049\)

\(=2106\)

Học Tốt !

54 x 133 x 45 x 133 + 133

= ( 54 + 45 + 1 ) x    133

=      100            x    133

=             13300

54 x 133 + 45 x 133 + 133

= 133 x ( 45 + 54 + 1 )

= 133 x 100

= 13300

54 x 133 + 45 x 133 + 133

= ( 54 + 45 + 1 ) x 133

= 100 x 133

= 13300

Đáp án: A

133 x 2 - 54 + 45

= 266 - 54 + 45

= 212 + 45

= 257

đ/s : 257

\(133\times2-54+45\)

\(=266-54+45\)

\(=257\)

133 x 2 - 54 + 45 = 266 - 54 + 45

                          = 212 + 45

                          = 257

\(\frac{132×145+100}{145×133-45}=1\)