a ) \(\frac{9}{8}:\frac{3}{7}\)

= \(\frac{9}{7}X\frac{3}{8}\)

= 

A)  \(\frac{5}{8}+\frac{7}{6}\)

= 

a) \(\frac{5}{8}+\frac{7}{6}\)

=  \(\frac{68}{48}\)

Nếu rút gọn thì bằng:\(\frac{17}{12}\)

b) 125 + 985 - 452 x 10

= 1110 - 4520

= - 3410

c) 1+ 2 + 3 +  4 + 5 + 6 + 7 + 8 + 9 + 10

= (1 + 9 ) + (2 + 8 ) + (3 + 7 ) + (4 + 6 ) + ( 5 + 10 )

= 10         +    10      +    10     +    10      +     10

= 10 x 5

= 50

a) 896 × 23 = 896 × (20 + 3)

= 896 × 20 + 896 × 3

= 17920 + 2688

= 20608

896 × 23 = 896 × (24 – 1 )

= 896 × 24 – 896 × 1

= 211504 – 896

= 20608

b) 547 × 38 = 547 × (30 + 8)

= 547 × 30 + 547 × 8

= 20786

547 × 38 = 547 × (39 – 1)

= 547 × 39 - 547 × 1

= 21333 – 547

= 20786

=452.(17+98-15)

=452.100

=45200

=452 x(17+98-15)

=452 x 100

=45200

\(452\times17+452\times98-452\times15\)
\(\Rightarrow452\times\left(17+98-15\right)\)
\(\Rightarrow452\times100\)
\(\Rightarrow45200\)

Đáp án là D

=-452-(-67+75-452)

=-452+67-75+452

=(452-452)+67-75

=0+67-75

=67-75

=-8

=-452-(-67+75-452)

=-452+67-75+452

=(452-452)+67-75

=0+67-75

=67-75

=-8

=-452-(-67+75-452)

=- 452 + 67 -75 + 452

=(452 - 452) + 67 - 75

=0 + 67 - 75

=67 - 75 =-8

\(452-\left(67-75+452\right)\)

\(=452-67+75-452\)

\(=-67+75\)

\(=8\)

\(452-\left(67-75+452\right)\\ =452-67+75-452\\ =\left(452-452\right)-67+75\\ =-67+75\\ =8\)

- 452 - ( - 67 + 75 - 452 )

= - 452 + 67 - 75 + 452

= [(- 452 ) + 452 ] + ( 67 - 75 )

=     0 + ( - 8 )

 =        - 8

mk đoán là -8 đúng ko 

= -452 + 67 - 75 + 452
= 67 - 75

= -8
Phá ngoặc đổi dấu, okeii><

-452-(-67+75-452)

=-452+67-75+452

=-8

-452 - ( -67 +  75 - 452 )

= -452 + 67 - 75 + 452

= ( -452 + 452 ) + ( 67 - 75 )

= 0 + ( -8 )

= -8