7v1+7v2=(0.02*v1-0.00001*v2)/(v1+v2),
7v1/v2+7=(0.02*v1/v2-0.00001)/(v1/v2+1)
令v1/v2=x
7x+7=(0.02x-0.00001)/(x+1)
7(x+1)(x+1)=(200x-1)/10000
70000(x^2+x+1)=200x-1
70000x^2+69800x+70001=0
判别式=69800^2-4*70000*70001
7v1+7v2=(0.02*v1-0.00001*v2)/(v1+v2),
7v1/v2+7=(0.02*v1/v2-0.00001)/(v1/v2+1)
令v1/v2=x
7x+7=(0.02x-0.00001)/(x+1)
7(x+1)(x+1)=(200x-1)/10000
70000(x^2+x+1)=200x-1
70000x^2+69800x+70001=0
判别式=69800^2-4*70000*70001