解方程 19-120%x=7 7/8x=21/40 x-28%x=3.6.
问题描述:
解方程 19-120%x=7 |
|
x-28%x=3.6. |
答
(1)19-120%x=7,
19-120%x+120%x=7+120%x,
19-7=7+120%x-7,
12÷120%=120%x÷120%,
x=10;
(2)
x=7 8
,21 40
x÷7 8
=7 8
÷21 40
,7 8
x=
;3 5
(3)x-28%x=3.6,
72%x=3.6,
72%x÷72%=3.6÷72%,
x=5.