Question

已知直线Y=KX+B与直线Y=3X-1交于X轴同一点,则K的值是?

Answer 1

既然相交于x轴,那么Y=0 所以:

1) 0=KX+B

0=3X-1

2) -B/K = X

1/3 = X

3) -B/K = 1/3

4) -3B = k

答：K= -3B