问题
解答题
解方程. (1)
(2)x+
(3)
(4)
|
答案
(1)
x+2x=5 8 3 4
(
+2)x=5 8 3 4
x=21 8 3 4
x÷21 8
=21 8
÷3 4 21 8
x=2 7
(2)x+
x=7 9
×2 3 1 2
(1+
)x=7 9 1 3
x=16 9 1 3
x÷16 9
=16 9
÷1 3 16 9
x=3 16
(3)
X-5 9
=3 4 1 4
X-5 9
+3 4
=3 4
+1 4 3 4
X=15 9
X÷5 9
=1÷5 9 5 9
X=9 5
(4)
X+5 7
X=422 7
(
+5 7
)X=422 7
X=42