Question

3/5+2(x+1/2009)=1/5,求代数式10-20(x+1/2009)的值

Answer 1

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