So 60*( x +0.03 )+90*(x-0.25 )=66.3 to solve x=0.58.
Therefore, the peak-valley electricity price is x +0.03=0.6 1, and the valley electricity price is x-0.25 =0.33.
If the new time-of-use electricity price policy is not implemented, the extra electricity fee paid by Xiaoming's family in April is 0.58*(60+90)=87.