利用内项之积等于外项之积
解:解方程,此方程的解为x = 4/45
∵X : Y = X ÷ Y = Z
∴2/3 : x = 5/4 : 1/6
2/3 ÷ x = 5/4 ÷ 1/6
2/3 ÷ x = 5/4 × 6
2/3 ÷ x = 15/2
x = 2/3 ÷ 15/2
x = 2/3 × 2/15
∴x = 4/45
答:此方程的解为x = 4/45
2/3:X=5/4:1/6
则2/3X=15/2
即3Xx15=2×2
则45X=4
则X=4/45
化作 5x:4=1:9
45x=4
X=4/45
2/3:x=5/4:1/6
5x/4=2/3×1/6
5x/4=1/9
x=1/9÷5/4
x=1/9×4/5
x=4/45