0.4:0.12 2/3:0.8 4/7:5/12化簡比(要過程)

0.4:0.12 2/3:0.8 4/7:5/12化簡比(要過程)


0.4:0.12
=40:12
=10:3
2/3:0.8
=2/3:4/5
=10:12
=5:6
4/7:5/12
=4/7x12/5
=48:35



k等於什麼時,代數式(1/4)k+5的值是(k-8)/3的值的2倍?


k=24.8