分析:根據(jù)比的基本性質(zhì)作答,即比的前項(xiàng)和后項(xiàng)同時(shí)乘一個(gè)數(shù)或除以一個(gè)數(shù)(0除外)比值不變.不同單位的數(shù)量的比,首先進(jìn)行名數(shù)的換算,然后化簡比.
解答:解:7.5:1.5,
=(7.5×2):(1.5×2),
=15:3,
=(15÷3):(3÷3),
=5:1;
:
,
=(
×16):(
×16),
=6:9,
=(6÷3):(9÷3),
=2:3;
:0.05,
=(
×40):(0.05×40),
=25:2;
1.2米=1.2×100厘米=120厘米,
1.2米:50厘米,
=120:50,
=(120÷10):(50÷10),
=12:5;
1.23:0.15,
=(1.23×100):(0.15×100),
=123:15
=(123÷3):(15÷3),
=41:5;
:
,
=(
×15):(
×15),
=12:8,
=(12÷4):(8÷4),
=3:2;
:0.75,
=
:
,
=(
×
):(
×
),
=2:1.
點(diǎn)評(píng):此題主要考查了化簡比的方法,另外還要注意化簡比的結(jié)果是一個(gè)比,它的前項(xiàng)和后項(xiàng)都是整數(shù),并且是互質(zhì)數(shù).