2題math = 40分 (1) urgent!

(1) If the slope is the same as L1,
Equation of L is 2x+5y +C =0 ----------(1) where c is constant
y-intercept of L2, when x = 0, -4y +8=0 +> y =2
Sub (0,2) into Eq(1);
2(0)+ 5(2)+C=0
C = =-10
Therefore, the equation L is 2x+5y-10 =0
(2) L: ax+by+6=0
slope of L: 3 = -a/b ------(1)
At y--intercept (0,4), => b(4) + 6 =0
b = -3/2
from Eq(1)
3 = -a/(-3/2)
a = 4.5




2007-09-21 21:02:53 補充：
下面那個答這題的人,將slope 的"負"號取消咗,所以佢個答案係錯