0.75x+ × =1 | 20-120% x=5 | x+ x=36 | (1- )x=60. |
×
=1,0.75x+
-
=1-
,0.75x÷0.75=
÷0.75,x=1;
(2)20-120% x=5,
20-120% x+120%=5+120%x,
20-5=5+120%x-5,
120%x÷120%=15÷120%,
x=12.5;
(3)x+
x=36,
x=36,
x×
=36×
,x=27;
(4)(1-
)x=60,
x=60,
x×
=60×
,x=105.
分析:(1)先化简0.75x+
=1,再根据等式的性质,方程两边同时除以0.75,即可解答;(2)根据等式的性质,方程两边同时加上120%x,然后再同时减去5,最后方程两边同时除以120%,即可解答;
(3)先化简
x=36,再根据等式的性质,方程两边同时乘
,即可解答;(4)先化简
x=60再根据等式的性质,方程两边同时乘
,即可解答.点评:本题主要考查了等式的性质,解答时要注意等号对齐.