[填空题]
The straight line, $L_1$, has the equation y=$\frac{1}{3}$x−5.
1.Write down the $y$-intercept of $L_1$. (a,b) a= b=
2.Write down the gradient of $L_1$. $mL_1$ =
The line $L_2$ is perpendicular to $L_1$ and passes through the point A(2,4).
3.Find the gradient of $L_2$. $mL_2$ =
4.Find the equation of $L_2$, giving your answer in the form ax+by+d=0,
where a,b,d∈Z. a = b = d =
