5/9:1/4x=7/8:4/51/4×7/8x=5/9×4/57/32x=4/9x=4/9÷7/32=4/9×32/7=128/63
5/9:1/4x=7/8:4/5
1/4x*7/8=5/9*4/5
7/32x=4/9
x=128/63