a, 16.(27+15)+8.(53+25):2
= 4.[(27+15).4] + 4.(53+25)
= 4.168 + 4.312
= 4.(168+312)
= 4.480=1920.
...
Câu b tình bt thui!
b, 53.(51+4)+53.53.(49+96)+53
=53.55+53.53.145+53
=2915+407305+53
=410220+53=410273
d,125.98.2.8.25
= 25.2.2.98.2.2.2.2.25.
= [(25.2.2.2)+(25.2.2.2)].98.
= (200 + 200).98.
= 400 . 98 = 39200.