Đáp án B

Đáp án là A

Đáp án A

Đáp án A

\(\left(49\cdot42-47\cdot42\right):42\)

\(=\left[\left(49-47\right)\cdot42\right]:42\)

\(=2\cdot42:42\)

\(=2\)

Con cặc

C

khi bỏ dấu ngoặc biểu thức 120+(-8)-(42-57) ta được:

A.120+8-42-57

B.120-8-42-57

C.120-8-42+57

D.120+8-42+57

Chọn C

\(42\times23+42+45\times42+30\times42-42\)

\(=\)\(42\times\left(23+42+45+30-42\right)\)

\(=\)\(42\times98\)

\(=\)\(4116\)

DE THE 4116 CAU DAY DE MA

\(\left(39\times42-37\times42\right):42\)

\(=\left[42\left(39-37\right)\right]:42\)

\(=42.2:42=84:42\)

\(=2\)

\(\left(39\cdot42-37\cdot42\right)\text{ : }42\)

\(=\left[42\left(39-37\right)\right]\text{ : }42\)

\(=\left[42\cdot2\right]\text{: }42\)

\(=84\text{ : }42\)

\(=2\)

\(\left(39\cdot42-37\cdot42\right)\text{ : }42\)

\(=\left[42\left(39-37\right)\right]\text{ : }42\)

\(=\left[42\cdot2\right]\text{: }42\)

\(=84\text{ : }42\)

\(=2\)

k nha mik biết làm nè

(39.42-37.42):42

=42.(39-37-1)

=42.1

=42

( 39 . 42 - 37 . 42 ) : 42

= [ 42 . ( 39 - 37 )] : 42

= 42 . 2 : 42 

= 2