Question

how do we tell the values of a and b in the following equation: ax + by = 1

they provide a graph with a line angled down and to the right like so \

the question is asking which of the following must be true:
1: a>0 and b< 0
2: a >0 and b > 0
3: a<0 and b <0
4: a <0 and b>0
5: a = 0 and b>0

Answer 1

when x is 0 b(y)=1... b = 1/y

Answer 2

a = 1/x when y = 0; you got 2 points now... just dont know what to do with them next :)

Answer 3

in the graph, where the line cross x=0?

Answer 4

to the right of the y axis

Answer 5

and the y intercept would be 1/b right?

Answer 6

(0,1/y) and (1/x, 0)

slope is equal to diff in y over diff in x

(1/y) - 0 1/y
-------- = ----
0 - (1/x) -1/x

Answer 7

y = -x/y + 1

Answer 8

so the correct answer is (4)

amistre, value of a is <0.

Answer 9

it is?...lol yay!!!

Answer 10

i got lost in my ramblings :)

Answer 11

lol!

Answer 12

ok, so how do you know whether b is positive or negative?

Answer 13

b = 1/y

y = -x/y + 1/y :) b is positive cause its where it hits the y axis.... i think

Answer 14

another question: the graph pass up or down y=0??

Answer 15

x + y^2 = 1 is what i think i get.... does that make sense?

Answer 16

y intercept is positive

Answer 17

a=1 and b=y ..... maybe :)

Answer 18

Rewrite

y=(-a/b)x + (c/b)

if c=1 and the line cross positive y axxis, b must be positive!

Answer 19

c=1 *** from text..

Answer 20

did you get?

Answer 21

ohhhh, yes i get it!

Answer 22

thank you so much!

Answer 23

you're welcome! I need to sleep.. see ya!