(145x99+145)-(143x101)

=(145x(99+1))-(143x(100+1))

=(145x100)-(143x100+143x1)

=   14500  -(14300+143)

=   14500-14443

=  57

k đi 

=

(145x99+145) - (143x101-143)

= 145 x (99+1)  - 143 x (101 - 1)

= 145 x 100 - 143 x 100

= (145 - 143) x 100

= 2 x 100

= 200

145 x ( 99 + 1)  - ( 143 x(101 -1)

= 145 x 100 - 143 x 100

= 14500 - 14300

=200

`#040911`

`b,`

`6 \times 1235 \times 20 - 5 \times 235 \times 24`

`= 6 \times (1000 + 235) \times 20 - 5 \times 235 \times 24`

`= 120 \times 1000 + 120 \times 235 - 120 \times 235`

`= 120 \times 1000 + 0`

`= 120000`

`c,`

\((145 \times 99+145)-143 \times 101-143\)

`=`\(145 \times 99 + 145 - 143 \times 101 - 143\)

`=`\(145 \times (99 + 1) - 143 \times (101 - 1)\)

`=`\(145 \times 100 - 143 \times 100\)

`=`\(100 \times (145 - 143)\)

`=`\(100 \times 2=200\)

`d,`

`54 \times 47 - 47 \times 53 - 20 - 27`

`= 54 \times 47 - 47 \times 53 - (20 + 27)`

`= 54 \times 47 - 47 \times 53 - 47`

`= 47 \times (54 - 53 - 1)`

`= 47 \times 0=0`

(145x99+145)-(143x102-143)

=145x100-143x101

=14500-14443

=57

\(\left(145x99+145\right)-\left(143x102-143\right)\)

\(=145x100-143x101\)

\(=14500-14443\)

\(=57\)

thanks nha

145 x 99 + 145

= 145 x ( 99 + 1 )

= 145 x 10

=1450

-HT-

à tớ nhầm là 

= 145 x 100

= 14500

nha ko phải là

= 145 x 10 đâu

ok Nguyễn Quỳnh Anh

145.99+143.101-143+145

=145.(99+1)+143.(101-1)

=145.100+143.100

=100.(145+143)

=100.288

=28800

HT

TL

= 28800

nhaaaaaaa

HT

2850

HT nhé

(145x99+145)-(143x101-143)

=145x(99+1)-143x(101-1)

=145x100-143x100

=14500-14300

=200

vì mọi số nhân vs 1 bằng chính nó mà

( 145 x 99 + 145 ) - ( 143 x 101 - 143 )

= ( 145 x ( 99 + 1 ) - ( 143 x ( 101 - 1 )

= 145 x 100 - 143 x 100

= 14500 - 14300

= 200

(145x99+145)-(143x101-143)=?

(145-145)x99-(143-143)x101

0x99-0x101

0-0=0

k minh dau tien