[填空题]
The coordinates of point A are (−1,−7)zur ownuphu4.ko8q.:rn12 a ) and the 0+fkm u idsa4r zij/jh0 5oz:9coordinates of point B are (5,2).0z:uj/ id +kzm5s0aio4 f h9rj $L_1$ is the line which passes through A and B.
1.Find the equation of $L_1$.
Point M is the midpoint of [AB]. The line $L_2$ is perpendicular to $L_1$ and passes through M. y = ax+b a= b =
2.Find the equation of $L_2$. y = ax+b a= b =
