解方程. x-3.6=1.44x=15x+0.42=4.2x÷1.4=0.5.
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解:(1)x-3.6=1.4,
???? x-3.6+3.6=1.4+3.6,
???????????? x=5;
(2)4x=15,
? 4x÷4=15÷4,
????? x=3.75;
(3)x+0.42=4.2,
x+0.42-0.42=4.2-0.42,
????????? x=3.78;
(4)x÷1.4=0.5,
x÷1.4×1.4=0.5×1.4,
????????? x=0.7.
解析分析:(1)等式两边同时加上3.6;
(2)等式两边同时除以4;
(3)等式两边同时减去0.42;
(4)等式两边同时乘1.4;即可得解.
点评:此题考查了解方程,利用等式的基本性质来解决问题.