Bài 49:

https://olm.vn/hoi-dap/question/9468.html

Bài 26:

b) Ư(-15) = {1; -1; 3; -3; 5; -5; 15; -15}

Bài 25:

a. 13 . (–7) = -91

b. (–8) . (–25) = 200

c. 25 . (–47) . (–4) = -1175 . (-4) = 4700

d. 8 . (125 – 3000) = 8 . (-2875) = -23000

e. 512 . (2 – 128) – 128 . (–512) = 512 . (-126) - 128 . (-512)

= -64512 - (-65536)

= 1024
f. 66 . 25 + 5 . 66 + 66 . 14 + 33 . 66 = 66 . {(25 + 5) + (14 + 33)}

= 66 . {30 + 47} = 66 . 77

= 5082

g. 12 . 35 + 35 . 182 – 35 . 94 = 35 . {(12 + 182) - 94}

= 35 . {194 - 94}

= 35 . 100 = 3500
h. (–8537) + (1975 + 8537) = -8537 + 1975 + 8537

= (-8537 + 8537) + 1975

= 0 + 1975 = 1975

i. (35 – 17) + (17 + 20 – 35) = 18 + 2

= 20