问题
解答题
求未知数X
|
答案
(1)
x-25%x=10,1 2
0.25x=10,
0.25x÷0.25=10÷0.25,
x=40;
(2)1÷(
x-4 5
)=3,1 5
1÷(
x-4 5
)×(1 5
x-4 5
)=3×(1 5
x-4 5
),1 5
1=
x-12 5
,3 5
1+
=3 5
x-12 5
+3 5
,3 5
=8 5
x,12 5
÷8 5
=12 5
x÷12 5
,12 5
x=
;2 3
(3)
=8 21
,0.4 x
8x=21×0.4,
8x=8.4,
8x÷8=8.4÷8,
x=1.05.