a) 18.17-36.7
= 18.17-18.2.7
=18.(17-14)
=18.3
=54
b) 54-6.(17+9)
=54-6.26
=6.9-6.26
=6.(9-26)
=6.(-17)
=-102
a) 18. 17 - 3.6.7
= 18 .17 - 18 .7
= 18.(17- 7)
= 18. 10
= 180
a) \(18\cdot17-3\cdot6\cdot7=18\cdot17-18\cdot7=18\left(17-7\right)=18\cdot10=180\)
b) \(54-6\left(17+9\right)=6\cdot9-6\left(17+9\right)=6\left(9-17-9\right)=6\cdot\left(-17\right)=-102\)
125.(-24)+24.225
cũng là tính nhanh nhé
54 - 6 .(17 + 9)
= 54 - 6 . 26
= 9 .6 - 6. 26
= 6 .(9 - 26)
= 6 . (-17)
= -120
Bài 1:
a) Ta có: \(18\cdot17-36\cdot7\)
\(=18\cdot17-18\cdot14\)
\(=18\cdot\left(17-14\right)\)
\(=18\cdot3=54\)
b) Ta có: \(54-6\cdot\left(17+9\right)\)
\(=6\cdot9-6\cdot\left(17+9\right)\)
\(=6\left(9-17-9\right)\)
\(=6\cdot\left(-17\right)=-102\)
