( 532×7 − 266 × 14 ) × ( 532 × 7 + 266 )

= ( 266 × 2 × 7 − 266 × 14 ) × ( 532 × 7 + 266 )

= ( 266 × 14 − 266 × 14 ) × ( 532 × 7 + 266 )

= 0 × 7 x ( 532 × 7 + 266 )

= 0

( 532 x 7 - 266 x 14 ) x ( 532 x 7 + 266 )

= ( 532 x 7 - 266 x 14 ) x ( 532 x 7 + 266 ) { cậu gạch số 14 và 7 in đậm và gạch chân }

= ( 532 x 1 - 266 x 2 ) x ( 532 x 7 + 266 ) { vì 14 : 7 =2 và 7 : 7 =1 }

= ( 532 - 532 )  x ( 532 x 7 + 266 )

= 0  x ( 532 x 7 + 266 )

= 0

Cậu ko phải ghi chỗ { ..... } đâu nha .

( 532 x 7 - 266 x 14 ) x ( 532 x 7 + 266 )

= ( 266 x 2 x 7 - 266 x 14 ) x ( 532 x 7 + 266 )

= ( 266 x 14 -266 x 14 ) x ( 532 x 7 + 266 )

= 0 x ( 532 x 7 + 266 )

= 0

              Bài làm :

Ta có :

(532x7-266x14)x(3+5+7+...+97+9)

=0x(3+5+7+...+97+9)

=0

(532×7-266×14)×(3+5+7+....+97+99)

=(3724-3724)×(3+5+7+.....+97+99)

=0×(3+5+7+...+97+99)

=0

Trả lời :

\(\left(532.7-266.14\right).\left(3+5+7+...+97+99\right)\)

\(=\left(266.2.7-266.7.2\right).\left(3+5+7+...+97+99\right)\)

\(=0.\left(3+5+7+...+97+99\right)\)

\(=0\)

Học tốt

(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`

 (145 x 99 + 145) - ( 143 x 101)

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

=( 145x100 ) - (143 x 100 + 143 x 1)

=   14500  - ( 14300+143)

=  57

a,=4x25x113-5x20x112

=100x113-100x112

=100x(113-112)=100x1=100

b,=113x(54+45+1)=113x100=11300

c,=(266x2x7-266x2x7)x(266x2x7+266)

=0x(266x2x7+266)=0