3/5+2(x+1/2009)=1/5,求代数式10-20(x+1/2009)的值
问题描述：
3/5+2(x+1/2009)=1/5,求代数式10-20(x+1/2009)的值
答
3/5+2(x+1/2009)=1/5
2(x+1/2009)=1/5-3/5
2(x+1/2009)=-2/5
10-20(x+1/2009)
=10-10*2(x+1/2009)
=10-10*(-2/5)
=10+4
=14