[問題]GWD4-Q26

[myron]

In the xy-plane, the line with equation ax + by + c = 0, where abc ≠ 0, has slope . What is the value of b?
(1) a = 4
(2) c = −6

不知該如何解?求救~~~~

[micht]

這題你少給了 slope=2/3 條件

y= (-ax-c)/b

slope= -a/b

所以 -a/b=2/3 知道A=4 那麼 b= -6

Ans: (A)

[myron]

我懂了，多謝你啦！

[Quinton]

感覺好像只要是二元一次方程式
只要想辦法弄成一元一次方程式都會充分
不管是哪種題
而另外一個條件∼總是無關痛癢的

[sugarcane]

y= (-ax-c)/b 這是哪裡來的
又怎會有這？？
slope= -a/b

[FrankChang]

y= (-ax-c)/b 這是哪裡來的
又怎會有這？？
slope= -a/b

哪裡來的...題目推來的ax + by + c = 0
平面上直線的表示y=mx+n,m為slope

[chris8888]

181. In the xy-plane, the line with equation ax + by + c = 0, where abc ≠ 0, has slope =2/3. What is the value of b?
(1) a = 4
(2) c = −6
Answer : (A)

題目應該是這樣....