0.538*50+0.568*40=49.62元
0.538*50+0.568*150+(t-200)*0.638
=0.638t-15.5
设用电x度,
0.538*50+0.568*150+(x-200)*0.638=83.7
x=155.486
0.538*50+0.568*40=49.62元
0.538*50+0.568*150+(t-200)*0.638
=0.638t-15.5
设用电x度,
0.538*50+0.568*150+(x-200)*0.638=83.7
x=155.486