Tinh Nhanh
cau 1 : 8x427x3 + 6x573x4
Cau 2 : 6x1235x20- 5x235x24
cau 3: 54x47-47x53-20-27
tính nhanh: b,6x1235x20-5x235x24
c,(145x99+145)-143x101-143
d,54x47-47x53-20-27
`#040911`
`b,`
`6 \times 1235 \times 20 - 5 \times 235 \times 24`
`= 6 \times (1000 + 235) \times 20 - 5 \times 235 \times 24`
`= 120 \times 1000 + 120 \times 235 - 120 \times 235`
`= 120 \times 1000 + 0`
`= 120000`
`c,`
\((145 \times 99+145)-143 \times 101-143\)
`=`\(145 \times 99 + 145 - 143 \times 101 - 143\)
`=`\(145 \times (99 + 1) - 143 \times (101 - 1)\)
`=`\(145 \times 100 - 143 \times 100\)
`=`\(100 \times (145 - 143)\)
`=`\(100 \times 2=200\)
`d,`
`54 \times 47 - 47 \times 53 - 20 - 27`
`= 54 \times 47 - 47 \times 53 - (20 + 27)`
`= 54 \times 47 - 47 \times 53 - 47`
`= 47 \times (54 - 53 - 1)`
`= 47 \times 0=0`
1.tính nhanh:
8x247x3+6x573x4 6x1235x20-5x235x24
(145x99+145)- (143x102-143) 54x47-47x53-20-27
a, 8 x 247 x 3 + 6 x 573 x 4
=24 x 247 + 24 x 573
=24 x ( 247 + 573 )
=24 x 820
=19680 ( mik nghĩ là bạn viết sai đề )
b, 6 x 1235 x 20 - 5 x 235 x 24
= 120 x 1235 - 120 x 235
= 120 x (1235 - 235)
=120 x 1000
=120000
c, ( 145 x 99 + 145 ) - ( 143 x 102 - 143 )
= [145 x ( 99+1)] - [ 143 x (102 - 1)]
= (145 x 100) - ( 143 x 100)
= (145 - 143) x 100
= 2 x 100
=200
d, 54 x 47 - 47 x 53 - 20 - 27
= 47 x (54 -53) - 20 - 27
= 47 x 1 - 20 - 27
= 47 - (20 + 27)
=47 - 47
=0
thật ra đề bài khó hơn nhưng tui cho dễ thôi
Bài 1 :
A, 8x427x3+6x573x46x1235x20-5x235x24
B, (145x99+145)-(143x102-143)-54x47-47x53-20-27
Các bạn giúp mik nha, ai trả lời nhanh nhất mik sẽ tik cho bạn đó !!!!
a)3906237648
b)-5019
Học tốt! k nha.
1.tính nhanh
2345 + 4257 -345 , 5238-476+3476 , 1987-538 -462 ,2376+3425-376-425 , 4276+2357+5724+7643
2.tính nhanh
125+125+125+125-25-25-25-25 ,45+45+45+45+15+15+15+15
3 .tính nhanh
425x3475+425x6525 , 257x432+257x354+257x214, 312x425+312x574+312
4 tính nhanh
8x427x3+6x573x4, (145x99+145)-(143x102-143), 54x47-47x53-20-27
tính nhanh
a) 45+45+45+45+15+15+15+15=
b) 125+125+125+125-25-25-25-25=
c) (145x99+145) -( 143x102-143) =
d) 54x47-47x53-20-27=
e)326x728+327x272=
a.45+45+45+45+15+15+15+15=45×4+15×4=4×(45+15)=4×60=240
125+125+125+125-25-25-25-25=125×4-25×4=4×(125-25)=4×100=400
57x47-47x53-20-27=
=>47(57-53)-20-27
=> 47.4-20-27
=>47.4-47
=>47.3
=> 141
t nha
57x47-47x53-20-27=57x47-47x53-47
=47x(57-53-1)=47x3=141
tinh b=(13/1/4-2/5/17-10/5/8+20/108)*(27/21+711/7)/(1/3/7+10/3):(12/1/3-14/2/7)
tinh b=(13/1/4-2/5/17-10/5/8+20/108)*(27/21+711/7)/(1/3/7+10/3):(12/1/3-14/2/7)
Tinh tong cac ao nguyen x biet
1/ -20<x<21
2/-18=<x=<17
3/-27<x=<27
4/ |x|=<3
5/ |x|<5
a,
=>x€{-19;-18;-17;-16;...;20}
=20
b,=>x€{-18;-17;-16;-15;-14;...;17}
x-18
c,
=>x€{-26;-25;-24;-23;-22;...;26}
=0
d
x€{3;2;1;0;-1;-2;-3;......}
=>|x|={3;1;2}
=>=6
e,x€{4;3;2;1;0;-1;-2;-3;-4;...}
=>|x|€{4;3;2;1;0}
=>=10