Question

tính bằng cách thuận tiện nhất 

428 x 97 + 428 x 2 + 428 

995 x 5 +4 x 5 +5 

655 x 6 - 355 x 6 

Answer 1

\(428\times97+428\times2+428\)

\(=428\times\left(97+2+1\right)\)

\(=428\times100\)

\(=42800\)

\(995\times5+4\times5+5\)

\(=5\times\left(995+4+1\right)\)

\(=5\times1000\)

\(=5000\)

\(655\times6-355\times6\)

\(=6\times\left(655-355\right)\)

\(=6\times300\)

\(=1800\)

Answer 2

428.97 + 428.2 + 428 

= 428.97+428.2+428.1

= 428.(97+2+1)

= 428.100

= 428

995.5 +4.5 +5 

= 995.5 +4.5 +5.1

= 5.(995+4+1)

= 5. 1000

= 5000

655.6 - 355.6 

= 6. ( 655-355)

= 6. 300

= 1800

Dấu " . " = x

@Cyy

Answer 3

428 x 97 + 428 x 2 + 428

= 428(97+2+1)

=428 x 100

= 42800

995 x 5 + 4 x 5 + 5

= 5(995+4+1)

= 5 x 1000

= 5000

655 x 6 - 355 x 6

=(655-355)x6

= 300 x 6

= 1800

Answer 4

$1)\; 428\times 97+428\times 2+428$

$=428\times \left(97+2+1\right)$

$=428\times 100$

$=42800$

995\times5+4\times5+52) 995×5+4×5+5

$=5\times \left(995+4+1\right)$

$=5\times 1000$

$=5000$

655\times6-355\times63) 655×6−355×6

$=6\times \left(655-355\right)$

$=6\times 300$

$=1800$