解方程 (1)2x-113/20+2.35=9 (2)x:7/10=0.3x+12.
问题描述:
解方程
(1)2x-1
+2.35=9 13 20
(2)x:
=0.3x+12. 7 10
答
(1)2x-1
+2.35=9,13 20
2x+0.7=9,
2x+0.7-0.7=9-0.7,
2x=8.3,
2x÷2=8.3÷2,
x=4.15;
(2)x:
=0.3x+12.7 10
x×
=0.3x+12,10 7
x=10 7
x+12,3 10
x−100 70
x=21 70
x-21 70
x+12,21 70
x=12,79 70
x×79 70
=12×70 79
,70 79
x=
,840 79
x=10
.50 79