分析:(1)根據(jù)等式的性質(zhì),兩邊同加上8.3,再同除以5即可;
(2)根據(jù)等式的性質(zhì),兩邊同加上1.02,再同除以2.3即可;
(3)先根據(jù)乘法分配律改寫成(1.9+0.4)X=9.2,即2.3X=9.2,再根據(jù)等式的性質(zhì),兩邊同除以2.3即可;
(4)根據(jù)等式的性質(zhì),兩邊同乘2,得15X=120,兩邊再同除以15即可;
(5)先根據(jù)乘法分配律改寫成(27+31)X=145,即58X=145,再根據(jù)等式的性質(zhì),兩邊同除以58即可;
(6)根據(jù)等式的性質(zhì),兩邊同加上2.8,再同除以3.2即可.
解答:解:(1)5X-8.3=10.7,
5X-8.3+8.3=10.7+8.3,
5X=19,
5X÷5=19÷5,
X=3.8;
(2)2.3X-1.02=0.36,
2.3X-1.02+1.02=0.36+1.02,
2.3X=1.38,
2.3X÷2.3=1.38÷2.3,
X=0.6;
(3)1.9X+0.4X=9.2,
(1.9+0.4)X=9.2,
2.3X=9.2,
2.3X÷2.3=9.2÷2.3,
X=4;
(4)15X÷2=60,
15X÷2×2=60×2,
15X=120,
15X÷15=120÷15,
X=8;
(5)27X+31X=145,
(27+31)X=145,
58X=145,
58X÷58=145÷58,
X=2.5;
(6)3.2X-2.8=6.2,
3.2X-2.8+2.8=6.2+2.8,
3.2X=9,
3.2X÷3.2=9÷3.2,
X=
.
點(diǎn)評(píng):此題考查了根據(jù)等式的性質(zhì)解方程,即等式兩邊同加、同減、同乘或同除以一個(gè)數(shù)(0除外),等式的左右兩邊仍相等;注意“=”上下要對(duì)齊.