解方程: (1)5x-18.5=1.3x (2)15:1/2=3x:4/5.
问题描述:
解方程:
(1)5x-18.5=1.3x
(2)15:
=3x:1 2
. 4 5
答
(1)5x-18.5=1.3x
5x-18.5+18.5=1.3x+18.5
5x-1.3x=1.3x-1.3x+18.5
3.7x=18.5
3.7x÷3.7=18.5÷3.7
x=5;
(2)15:
=3x:1 2
4 5
x=15×3 2
4 5
x÷3 2
=12÷3 2
3 2
x=8.