From.1 數學

5 : 6 = z : 4
5 / 6 = z / 4
6z = 5(4)
6z = 20
z = 20/6
z = 10/3 //
2) 若 2x :3y = 5 : 6 , 則 x : y 等於?
2x :3y = 5 : 6
2x / 3y = 5 / 6
(2/3)(x/y) = 5/6
x / y = (5/6)(3/2)
x / y = 15 / 12
x : y = 15 : 12
x : y = 5 : 4 //
3) 若 9 : 1 = ( 8x + 8 ) : 10 , 求 x 的 值 。
9 : 1 = ( 8x + 8 ) : 10
9 / 1 = ( 8x + 8 ) / 10
8x + 8 = 10(9)
8x + 8 = 90
8x = 82
x = 82/8
x = 41/4 //

2007-04-15 19:01:40 補充：
小提示:1. a : b = a / b ( b分之 a )2. 如 a / b = c / d, 則 ad = bc

1)5:6=z:4
6z=4(5)
6z=20
z=20/6
1
z=3---
3
2)2x:3y=5:6
3y5=6(2)x
15y=12x
y:x=15:12
y:x=5:4
3)9:1=(8x+8):10
90:10=(8x+8):10
90=8x+8
8x+8=90
8x=82
x=10.25

1)z=1/3
2)x=2又1/2 y=2
3)x=10又1/4

1) 5/6 = z/4
6z = 20
z = 10/3
2) 2x:3y=5:6
15y = 12x
5/4 = x/y
x:y = 5:4
3) 8x+8 = 90
8x= 82
x = 41/4