Question

Using intercepts to graph linear equations: y = 1/2x - 1

To find y: y = 1/2x - 1
y = 1/2(0) - 1
y = -1 (-1,0)
Confused about finding x. If I've done the math correctly then x = -1?

Answer 1

are you trying to find the x and y-intercepts?

Answer 2

if so, to find one, set the other variable to zero

Answer 3

so you did the y-int right

Answer 4

yes to x and y intercepts "slope and y intercepts"

Answer 5

so for x, set the y to zero, and solve for the variable x

Answer 6

when i do that i get x = 1/2 (0, 1/2)

Answer 7

can you type out your work?

Answer 8

mine:
0 = (1/2)x -1; add 1 to both sides
1 = (1/2)x; multiply both sides by 2
2 = x

Answer 9

Thank you, but could you please explain how you got 2. will be working the problem while u type

Answer 10

and actually, your y-int would be (0,-1)

Answer 11

your original equation was y = (1/2)x - 1, yes?

Answer 12

yes

Answer 13

when you set y to 0, you get the equation
0 = (1/2)x -1; from here on you use algebra to solve for x
add 1 to both sides

Answer 14

to get
1 = (1/2)x
multiply both sides by 2 to get
2 = x

Answer 15

ahh o.k. but what about the -1?

Answer 16

i added that to both sides in the first step

Answer 17

so your x-int is (2,0)
and your y-int is (0,-1)
do you get why?

Answer 18

OHHHH now i get it: after multiplying y by 0 you get 0 = 1/2x - 1. Next you add one to both sides to get 1 = 1/2x. and when u multiply both sides by 2 you get 2 = x

yes i get why now. had to work it in my head and on paper to understand

Answer 19

technically it's not multiply y by 0, you just do that because you assume that your y coordinate of the x-intercept will be zero, otherwise your point would not fall on the x-axis.

Answer 20

but everything else is right, im glad you understand

Answer 21

ty so much for your patience and help.

Answer 22

you're welcome