Giusp mk hêt nha
A. Dạng 1: Tinh nhanh ( Rút thừa số chung)
* 24 x 5 + 24 x 3 + 24 x 2
* 24 x 5 + 24 x 4 + 24
* 217 x 45 + 50 x 217 + 207 x 5
* 456 x 36 + 456 x 61 + 4 x 456 + 456
* (16 x 6+ 16 x3 + 16) – (12 x 65 + 12 x 3 + 2 x12)
* (16 x 6+ 16 x3 + 16) – 12 x 65 – 12 x 3 – 2 x12
* 213 x 37 + 213 x 39 + 23 x 213 + 213
* 9 + 9 x 3 + 18 : 2 x 6
* 2007 x 16 – 2007 x 14 – 2007 x 2 + 2007
* 3 x 9 + 18 x 2 + 2 x 9 + 9
* ( 145 x 99 + 145) – ( 143 x 101 – 143 )
* 2006 x ( 43 x 10 – 2 x 43 x 5) + 100
* 64 x 4 + 18 x 4 + 9 x 8
* 44 x 5 + 18 x 10 + 20 x 5
* 3 x 4 + 4 x 6 + 9 x 2 + 18
* 2 x 5 + 5 x 7 + 9 x 3
* 15 : 5 + 27 : 5 + 8 : 5
* 99 : 5 – 26 : 5 – 14 : 5
B. Dạng 2 : Tính nhanh ( Một vế bằng 0 )
* ( 18 – 9 x 2) x ( 2 + 4 + 6 + 8 + 10 )
* ( 7 x 8 – 56 ) : ( ………………………….)
* ( ………………………………) x ( 42 – 6 x 7 )
*( 12 x 6 – 12 x 4 – 12 x 2 ) x ( ……………………………..)
*(a x 7 + a x 8 – a x 15) : ( 1 + 2 + 3 + …….. + 10)
*58 – 58 x( 6 + 54 – 60)
* 32 + 63 x a x ( a x 1 – a : 1) + 32 x 8 + 32
* ( 1 + 2 + 3 + 4 + …. + 9 ) x ( 21 x 5 – 21 – 4 x21)
* ( 9 x 7 + 8 x 9 – 15 x 9 ) : ( 1 + 3 + 5 + 7 + ……..+ 17 + 19 )
* ( 2 + 4 + 6 + 8 + … + 20 ) x ( 56 x 3 – 72 : 9 x 21)
Giusp mk hêt nha A. Dạng 1: Tinh nhanh ( Rút thừa số chung) * 24 x 5 + 24 x 3 + 24 x 2 * 24 x 5 + 24 x 4 + 24 * 217 x 45 + 50 x 217 + 207 x 5 * 456 x
By Samantha
A:
*24 x 5 + 24 x 3 + 24 x 2= 24 × (5+3+2)= 24×10=240
* 24 x 5 + 24 x 4 + 24=24 x 5 + 24 x 4 + 24×1=24×(5+4+1)=24×10=240
* 217 x 45 + 50 x 217 + 207 x 5= 217×(45+50) +207 ×5=217×95+207+5 =20615 +1035=21650
* 456 x 36 + 456 x 61 + 4 x 456 + 456
= 456 x 36 + 456 x 61 + 4 x 456 + 456 ×1
= 456×(36+61+4+1)
=456×102=46512
* (16 x 6+ 16 x3 + 16) – (12 x 65 + 12 x 3 + 2 x12)
=(16 x 6+ 16 x3 + 16×1) – (12 x 65 + 12 x 3 + 2 x12)
=[16×(6+3+1)]-[12×(65+3+2)]
=(16×10)-(12×70)
=160×840=134 400
* 213 x 37 + 213 x 39 + 23 x 213 + 213
=213 x 37 + 213 x 39 + 23 x 213 + 213 ×1
=213×(37+39+23+1)
=213×100=21300
* 9 + 9 x 3 + 18 : 2 x 6= 9×1 +9×3+9×2 : 2 x 6=9×(1+3+2 : 2 x 6)=9×10=90
* 2007 x 16 – 2007 x 14 – 2007 x 2 + 2007
=2007 x 16 – 2007 x 14 – 2007 x 2 + 2007×1
=2007×(16-14-2+1)
=2007×1=2007
* 3 x 9 + 18 x 2 + 2 x 9 + 9=3 x 9 + 9x 2×2 + 2 x 9 + 9×1=9×(3+2×2+2+1)=9×10=90
* ( 145 x 99 + 145) – ( 143 x 101 – 143 )
=( 145 x 99 + 145×1) – ( 143 x 101 – 143 ×1)
=[145×(99+1)]-[143×(101-1)]
=145×100-143×100
=(145-143)×100
=2×100=200
* 2006 x ( 43 x 10 – 2 x 43 x 5) + 100=2006×0+100=100
* 64 x 4 + 18 x 4 + 9 x 8= 64 x 4 + 18 x 4 + 9 x 2×4=(64+18+9×2)×4=100×4=400
* 44 x 5 + 18 x 10 + 20 x 5 =44 x 5 + 18 x 5×2+ 20 x 5 =(44+18×2+20)×5=100×5=500
* 3 x 4 + 4 x 6 + 9 x 2 + 18=3 x 4 + 4 x 3×2 + 3×3 x 2 + 3×6=3×(4+4×2+3×2+6)=3×24=72
* 2 x 5 + 5 x 7 + 9 x 3=5×(2+7)+9×3=5×9+9×3=9×(5+3)=9×8=72
* 15 : 5 + 27 : 5 + 8 : 5 =$\frac{(15+27+8)}{5}$ =$\frac{50}{5}$ =10
* 99 : 5 – 26 : 5 – 14 : 5=$\frac{(99-26-14)}{5}$ =$\frac{59}{5}$
B:
* ( 18 – 9 x 2) x ( 2 + 4 + 6 + 8 + 10 )=(18-18)x ( 2 + 4 + 6 + 8 + 10 )=0x ( 2 + 4 + 6 + 8 + 10 )=0
⇒ Tương tự như trên mấy bài tập phía dưới mình làm nhanh nhé
* ( 7 x 8 – 56 ) 🙁 2 + 4 + 6 + 8 + 10 )
=0: ( 2 + 4 + 6 + 8 + 10 )=0
* ( 7 x 8 – 56 )x ( 42 – 6 x 7 )=0×0=0
*( 12 x 6 – 12 x 4 – 12 x 2 ) x ( 42 – 6 x 7 )=( 12 x 6 – 12 x 4 – 12 x 2 ) x0=0
*(a x 7 + a x 8 – a x 15) : ( 1 + 2 + 3 + …….. + 10)
=[a×(7+8-15)]: ( 1 + 2 + 3 + …….. + 10)
=0: ( 1 + 2 + 3 + …….. + 10)=0
*58 – 58 x( 6 + 54 – 60)=58 – 58 x0=58-0=58
* 32 + 63 × a × ( a × 1 – a : 1) + 32 x 8 + 32=32 + 63 × a × 0+ 32 x 8 + 32=32 +0+ 32=64
* ( 1 + 2 + 3 + 4 + …. + 9 ) x ( 21 x 5 – 21 – 4 x21)
=( 1 + 2 + 3 + 4 + …. + 9 ) x ( 21 x 5 – 21 ×1- 4 x21)
=( 1 + 2 + 3 + 4 + …. + 9 ) x[21×(5-1-4)]
=( 1 + 2 + 3 + 4 + …. + 9 )×0=0
* ( 9 x 7 + 8 x 9 – 15 x 9 ) : ( 1 + 3 + 5 + 7 + ……..+ 17 + 19 )
=[9×(9+7+8-15)]: ( 1 + 3 + 5 + 7 + ……..+ 17 + 19 )
=0: ( 1 + 3 + 5 + 7 + ……..+ 17 + 19 )=0
* ( 2 + 4 + 6 + 8 + … + 20 ) x ( 56 x 3 – 72 : 9 x 21)
= ( 2 + 4 + 6 + 8 + … + 20 ) x(8×7×3-8×9:9×21)
=( 2 + 4 + 6 + 8 + … + 20 ) x[8×(7×3-9:9×21)]
=( 2 + 4 + 6 + 8 + … + 20 )×(8×0)
=( 2 + 4 + 6 + 8 + … + 20 )×0=0
Học Tốt Nhé
Dạng1
$*24×5+24×3+24×2\\=24×(5+3+2)\\=24×10=240$
$*24×5+24×4+24\\=24×(5+4+1)\\=24×10=240$
$*217×45+50×217+217×5\\=217×(45+50+5)\\=217×100=21700$
$*456×36+456×61+4×456+456\\=456×(36+61+4+1)\\=456×100=45600$
$*(16×6+16×3+16)-(12×5+12×3+2×12)\\=16×(6+3+1)-(12×(5+3+2)\\=16×10-12×10\\=10×(16-12)\\=10×4=40$
$*(16×6+16×3+16)-12×5-12×3-2×12\\=16×(6+3+1)-12×(5+3+2)\\=16×10-12×10\\=10×(16-12)\\=10×4=40$
$*213×37+213×39+23×213+213\\=213×(37+39+23+1)\\=213×100=21300$
$*9+9×3+18:2×6\\=9×(1+3+6)\\=9×10=90$
$*2007×16-2007×14-2007×2+2007\\=2007×(16-14-2+1)\\=2007×1=2007$
$*3×9+18×2+2×9+9\\=9×(3+4+2+1)\\=9×10=90$
$*(145×99+145)-(143×101-143)\\=145×(99+1)-143×(101-1)\\=145×100-143×100\\=100×(145-143)\\=100×2=200$
$*2006×(43×10-2×43×5)+100\\=2006×(43×10-43×10)+100\\=2006×0+100=100$
$*64×4+18×4+9×8\\=4×(64+18+18)\\=4×100=400$
$*44×5+18×10+20×5\\=5×(44+36+20)\\=5×100=500$
$*3×4+4×6+9×2+18\\=4×(3+6)+9×(2+2)\\=4×(3+6+9)\\=4×18=72$
$*2×5+5×7+9×3\\=5×(2+7)+9×3\\=9×(5+3)\\=9×8=72$
$*15:5+27:5+8:5\\=(15+27+8):5\\=40:5=8$
$*99:5-26:5-14:5\\=(99-26-14):5\\=59:5$
Dạng 2
$*(18-9×2)×(2+4+6+8+10)\\=(18-18)×(2+4+6+8+10)\\=0×(2+4+6+8+10)=0$
$*(7×8-56):(………)\\=(56-56):(…….)\\=0:(………)=0$
$*(…..)×(42-6×7)\\=(…..)×(42-42)\\=(…..)×0=0$
$*(12×6-12×4-12×2)×(…..)\\=(12×(6-4-2)×(…..)\\=(12×0)×(…..)\\=0×(…..)=0$
$*58-58×(6+54-60)\\=58-58×0=58$
$*32+63×a×(a×1-a:1)+32×8+32\\=32×(1+8+1)+63×a×(a-a)\\=32×10+63×a×0\\=320$
$*(1+2+3+4+…+9)×(21×5-21-4×21)\\=(1+2+3+4+…+9)×(21×(5-1-4))\\=(1+2+3+4+…+9)×(21×0)\\=(1+2+3+4+…+9)×0=0$