Question

Tính hợp lí:

a, 25 - (-75)  + 32 - (32+75) 

b, 34 . (15-10)  -15 . (34-10) 

Answer 1

a) 25 + 75 + 32 - 32 - 75 

= (75-75) + (32-32) + 25

= 25

b) 34 . 15 - 34 . 10 - 15 . 34 - 15 . -10

= -10 . (34+15) - 15 (-34+34)

=-490

Answer 2

a) 25 + 75 + 32 - 32 - 75 

= (75-75) + (32-32) + 25

= 25

b) 34 . 15 - 34 . 10 - 15 . 34 - 15 . -10

= -10 . (34+15) - 15 (-34+34)

=-490

Answer 3

a) 25 - (-75) + 32 - (32 + 75)

= 25 + 75 + 32 - 32 - 75

= 25 + ( 75 - 75) + ( 32 - 32)

= 25 +  0            + 0

= 25

b) 34. (15 - 10) - 15. ( 34 -10)

= 34.15 - 34.10 - 15. 34 -15.10

= 34.10 + 15.10

= 10. ( 34 + 15)

=10. 49

= 490

Answer 4

a,\(25-\left(-75\right)+32-\left(32+75\right)\)

\(=25+75+32-32-75\)

\(=25+\left(32-32\right)+\left(75-75\right)\)

\(=25\)

b,\(34.\left(15-10\right)-15.\left(34-10\right)\)

\(=34.15-34.10-34.15-15.10\)

\(=34.\left(15-10-15\right)-15.10\)

\(=34.\left(-10\right)+15.\left(-10\right)\)

\(=-10.\left(34+15\right)=-10.49=-490\)