Bài 1
415+378+263+622+585+737
=(415+585)+(378+622)+(263+737)
=1000+1000+1000
=3000
215x7-215x2+5x215
=215x(7-2+5)
=215x10
=2150
27x3+81x2+27
=27x3+27x6+27
=27x(3+6+1)
=27x10
=270
TICK CHO MÌNH NHÉ
415 + 378 + 263 + 622 + 585 + 737
= ( 415 + 585 ) + ( 378 + 622 ) + ( 263 + 737 )
= 1000 + 1000 + 1000
= 3000
TICK CHO MÌNH NHÉ
215 x 7 - 215 x 2 + 5 x 215
= 1505 - 430 + 1075
= ( 1505 + 1075 ) - 430
= 2580 - 430
= 2150
Bài 1:
a) Ta có: \(415+378+263+622+585+737\)
\(=\left(415+585\right)+\left(378+622\right)+\left(263+737\right)\)
\(=1000+1000+1000=3000\)
b) Ta có: \(215\cdot7-215\cdot2+5\cdot215\)
\(=215\left(7-2+5\right)\)
\(=215\cdot10=2150\)
c) Ta có: \(27\cdot3+81\cdot2+27\)
\(=27\left(3+3\cdot2+1\right)\)
\(=27\cdot10=270\)
