Tính: -65.(87 - 17) - 87.(17 - 65)
tính nhanh:
a)-65.(87-17) - 87.(17-65)
b)87.(13-18) - 13.(87+18)
tính nhanh: -65 .(87-17)-87.(17-65)
-65.(87 - 17) - 87.(17 - 65) = 65.(17 - 87) - 87.17 + 87.65 = 65.17 - 65.87 + 65.87 - 87.17 = (65 - 87).17 = -22.17 = -374
Tính nhanh
-65.(87-17)-87.(17-65)
-65 . 87 - (-65 . 17) - 87.17 + 87.65
= -65 . 87 + 65 . 17 - 87 . 17 + 87 . 65
= 87 . (-65 + 65) + 17 . (65 - 87)
= 87 . 0 + 17 . (-22)
= 0 + (-374)
= -374
=-65*87-(-65*17)-87*17-87*(-65)
=[-65*87-87*(-65)]-(-65*17+87*17)
=0-17*(-65+87)
=0-17*22
=0-374
=-374
17-65.(87-17)-87.(17-65)
17-65.(87-17)-87.(17-65)
=17-65.87-17.87.17-65
=(17-17).(65-65).(87-87)-17
=0.0.0-17
=0-17
=-17
87-17.(-65)+(-87).(17-65)
-65*(87-17)-87*(17-65)
=-65.87+65.17-87.17+65.87=
=17(65-87)=-17.22
-65 . ( 87 -17 ) -87 . ( 17 - 65 )
-65 . ( 87 -17 ) -87 . ( 17 - 65 )
=(-65).70-87.(-48)
=(-4550)-(-4176)
=(-374)
\(-65.\left(87-17\right)-87.\left(17-65\right)\)
\(=-65.70-87.\left(-48\right)\)
\(=\left(-4550\right)-\left(-4176\right)=-374\)
-65.(87-17)-87.(17-65)
-65.(87-17)-87.(17-65)
=-65.87+65.17-87.17+87.65
=65.(-87+87)+17.(65-87)
=67.0+17.(-22)
=0-374
=-374
-65.(87-17)-87.(17-65)
=-65.70-87.(-48)
=-4550+4176
=-374
65.(87-17)+87.(17-65)
65 . (87 - 17) + 87 . (17 - 65)
= 65 . 87 - 65 . 17 + 87 . 17 - 87 . 65
= 65 . (87 - 17 - 87) + 87 . 17
= 65 . (-17) + 87 . 17
= (-65) . 17 + 87 . 17
= 17 . (-65 + 87)
= 17 . 22
= 374