Question

Need a little help with the following questions:

1.
Write an equation in standard form for a line with a slope of 1/2 and passing through A(1,2).
A. x-2y-3=0
B. x-2y+3=0
C. -x+2y+3=0
D. -x-2y+3=0
2.
Which is an equation for the line passing through B(0,3) and C(-3,4)?
A. x-3y-9=0
B. 3x-y-3=0
C. 3x+y-3=0
D. x+3y-9=0

Answer 1

I think a graph or something is needed?

Answer 2

use point slope formula
y - y1 = m(x - x1)
slope(m) = 1/2
(1,2) x1 = 1 and y1 = 2
now lets sub
y - 2 = 1/2(x - 1)
y - 2 = 1/2x - 1/2
y = 1/2x - 1/2 + 2
y = 1/2x - 1/2 + 4/2
y = 1/2x + 3/2

multiply the equation by 2
2y = x + 3
-x + 2y = 3
x - 2y = 3
x - 2y - 3 = 0 <-- answer

Answer 3

do you have any questions about this one ?

Answer 4

Why do you multiply the equation by 2?

Answer 5

to get rid of the fractions you multiply the whole equation by the LCD

Answer 6

Oh got it, didn't see that. Thank you so much.

Answer 7

you ready for the second problem

Answer 8

I can get the slope of the two points, can I use any of the two points to sub?

Answer 9

there is a slope formula :
slope(m) = (y2 - y1) / (x2 - x1)
(0,3) x1 = 0 and y1 = 3
(-3,4) x2 = -3 and y2 = 4
now just sub
slope(m) = (4 - 3) / (-3 - 0)
can you finish and find the slope ?

Answer 10

Slope would be 1/-3, if that's correct I got the rest.

Answer 11

slope is -1/3

Answer 12

Alright, makes sense. Thank you

Answer 13

your very welcome....you sure you got the rest ?

Answer 14

tag me if you run into problems