求未知数x (1)x+2/3x=15; (2)x-7/9x=4/3.
问题描述:
求未知数x
(1)x+
x=15; (2)x-2 3
x=7 9
. 4 3
答
(1)x+
x=152 3
x=155 3
x×5 3
=15×3 5
3 5
x=9
(2)x-
x=7 9
4 3
x=2 9
4 3
x×2 9
=9 2
×4 3
9 2
x=6