tinh bang cach thuan tien nhat
a 4 / 2 x 4 + 4 / 4 x 6 + 4 / 6 x 8 + ...... + 4 / 96 x 98
tinh bang cach thuan tien nhat : 3/4 x 4/5 + 5/6 x 6/7 x 7/8
tinh bang cach thuan tien nhat
8,12 x 6 + 16,24 x 4 - 4,06 x 8
8,12 x 6 + 16,24 x 4 - 4,06 x 8
=48,72 + 64,96 - 32,48
= 113,68 - 32,48
=81 ,2
Tinh gia tri bieu thuc bang cach thuan tien nhat :
A= 1/10 x 2/9 x 3/8 x 4/7 x 5/6 x 6/5 x 7/4 x 8/3 x 9/2
giup minh
tinh bang cach thuan tien
3/7 x 5/6 + 4/7 x 5/6
3/7*5/6+4/7*5/6
=5/6*(3/7+4/7)
=5/6*1
=5/6
3/7*5/6+4/7*5/6
= 5/6*(3/7+4/7)
=5/6*1
=5/6
Tinh bang cach thuan tien nhat:
a) 1/3 + 1/4 + 2/3 + 3/4
b) 1/2 + 1/3 - 1/5 + 1/6
c) 2/3 x 4/5 + 1/3 x 4/5
d) 2/3 x 4/5 - 1/3 x 4/5
a)1/3+1/4+2/3+3/4
=(1/3+2/3)+(1/4+3/4)
=1+1
=2.
b)1/2+1/3-1/5+1/6
=(1/2+1/3+1/6)-1/5
=1-1/5
=4/5
c)2/3x4/5+1/3x4/5
=4/5x(2/3+1/3)
=4/5x1
=4/5
d)2/3x4/5-1/3x4/5
=4/5x(2/3-1/3)
=4/5x1/3
=4/15
144 x 4+18 x 46 x 8 - 44x 32 - 44x 58
Tinh bang cach thuan tien nha
tinh bang cach thuan tien;
1234+1357+3456+9753
1+2+3+...+99+100
2+4+6+...+98+100
a) = (1234+3456)+(1357+9753)
= 4690+11110
= 15800
b
tớ góp ý cho cậu là gép cặp vào cho thành số tròn chục thì ra
1234+1357+3456+9753
= ( 1234 + 3456 ) + ( 1347 + 9753 )
= 5000 + 10 000
= 15 000
1+2+3+...+99+100
= ( 1 + 100 ) + ( 2 + 99 ) + ... + ( 50 + 51 )
50 Cặp số
= 101 x 50
= 5 050
2+4+6+...+98+100
= ( 2 + 100 ) + ( 4 + 98 ) + ... + ( 48 + 52 )
25 cặp số
= 102 x 25
= 2550
2+3+...+99+1002+4+6+...+98+100
= (
1+2+3+4+5+6+7+8+9
tinh bang cach thuan tien nhat
1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9
= (1 + 9) + (2 + 8) + (3 + 7) + (4 + 6) +5
= 10 + 10 + 10 +10 + 5
= 10 x 4 + 5
= 40 + 5
= 45
1+2+3+4+5+6+7+8+9
=[1+9]+[2+8]+[3+7]+[4+6]+5
=10+10+10+10+5
=40+5
=45
tinh bang cach thuan tien nhat :
5,6 x 4 + 5,6 x3 + 5,6 x 2 + 5,6
nhanh do
5,6 x 4 + 5,6 x3 + 5,6 x 2 + 5,6=5,6x(4+3+2+1)=5,6x10=56
5 , 6 x 4 + 5 , 6 x 3 + 5 , 6 x 2 + 5 , 6
= 5 `
\(5,6.4+5,6.3+5,6.2+5,6\)
\(=5,6.4+5,6.3+5,6.2+5,6.1\)
\(=5,6.\left(4+3+2+1\right)\)
\(=5,6.10\)
\(=56\)