=3.7.3.5-2.3.5
=3.5(3.7-2)
=35.19
=35.(20-1)
=35.20-35
=700-35=665
a) \(21.35-2.3.5\)
\(=3.7.7.5-2.3.5\)
\(=3.5.\left(7.7-2\right)\)
\(=15.\left(49-2\right)\)
\(=15.47=705\)
a, 21 . 35 - 2 . 3 . 5
= 7 . 3 . 7 . 5 - 2 . 3 . 5
= 5 . 3 ( 7 . 7 - 2 )
= 15 . 47
= 705
~~~Chúc bạn hok tốt ~~~