tinh bang cach thuan tien nhat : 3/4 x 4/5 + 5/6 x 6/7 x 7/8
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
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
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
tinh bang cach thuan tien nhat : 1+2-3-4+5+6-7-8+9+...+2013+2014-2015-2016
( 5 + 10 + 15 + 20 + 25 + 30 + 35 ) x ( 42 - 6 x 7 )
tinh bang cach thuan tien nhat
( 5 + 10 + 15 + 20 + 25 + 30 + 35 ) x ( 42 - 6 x 7 )
= ( 5 + 10 + 15 + 20 + 25 + 30 + 35 ) x ( 42 - 42 )
= ( 5 + 10 + 15 + 20 + 25 + 30 + 35 ) x 0
= 0
tinh bang cach thuan tien nhat
1+2+3+4+5+6+7+8+9:9 =
1+2+3+4+5+6+7+8+9:9
=1+2+3+4+5+6+7+8+1
=(1+1)+(2+8)+(3+7)+(4+6)+5
=2+10+10+10+5
=(2+5)+(10+10+10)
=7+30
=37
1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 : 9
= ( 1 + 9 ) + ( 2 + 8 ) + ( 3 + 7 ) + ( 4 + 6 ) + 5 : 9
= 10 + 10 + 10 + 10 + 5 : 9
= 20 + 20 + 5 : 9
= 40 + 5 : 9
= 45 : 9
= 5
tinh bang cach thuan tien nhat a.3/5+4/7+2/5+1/7+2/7 b.1/3+1/6+4/3+2/6+2/3
Tinh bang cach thuan tien nhat:
a/ 7,8 x 34,5 + 15,5 x 7,8
b/ 3/7 x 11/5 + 4/7 x 11/5
a/ = 7,8 x ( 34,5 + 15,5 ) = ..... tự tính
b/ 11/5 x (3/7 +4/7 )= .......tự tính
mk nhé
a, 7,8 x 34,5 +15,5 x 7,8 = 7,8 x ( 34,5 + 15,5) =7,8 x 50 =390
b, 3/7 x 11/5 +4/7 x 11/5 = 11/5 x ( 3/7 +4/7) = 11/5 x1=11/5
=.= hok tốt!!
7,8 . (34,5 + 15,5 )
= 7,8 .50.0
=39,000
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