e
, 11-12 +13-14 +15-16 +17-18+19-20
= (11-12) +(13-14) +(15-16) +(17-18) +(19-2)
= - 1 . 4 + (19-2)
= 4 + 17
= 21
e)Ta có 11-12+13-14+15-16+17-18+19-20
=(11-12)+(13-14)+(15-16)+(17-18)+(19-20)
= (-1) + (-1) + (-1) + (-1) + (-1)
= (-1) . 5
= -5
f) Ta có -3752-(29-3632)-51
= -3752-29+3632-51
= -100-29-51
= -129 -51
=-180