Bài 2
9+9.3+18:2.6
=9.4+9.6
=9.(4+6)
=9.10
=90
3.9+18.2+2.9+9
=3.9+9.4+9.3
=9.(3+4+3)
=9.10
=90
44.5+18.10+20.5
=22.10+18.10+10.10
=10.(22+18+10)
=10.50
=500
1.
= 9 + 27 + 9 . 6
= 9 + 27 + 54
= 90
2.
= 27 + 18 . 2 + 2 . 9 + 9
= 27 + 36 + 18 + 9
= 90
3.
= (44 x 5) + (18 x 10) + (20 x 5)
= 220 + 180 + 100
= 500
Bài 2:
a) Ta có: \(9+9\cdot3+18:2\cdot6\)
\(=9+9\cdot3+9\cdot6\)
\(=9\left(1+3+6\right)\)
\(=9\cdot10=90\)
b) Ta có: \(3\cdot9+18\cdot2+2\cdot9+9\)
\(=3\cdot9+4\cdot9+2\cdot9+9\)
\(=9\left(3+4+2+1\right)\)
\(=9\cdot10=90\)
c) Ta có: \(44\cdot5+18\cdot10+20\cdot5\)
\(=44\cdot5+36\cdot5+20\cdot5\)
\(=5\left(44+36+20\right)\)
\(=5\cdot100=500\)