# algebra review!

posted by trixie

it says write the equation of the vertical line that passes through the point (7,-3). what do i need to start it off?

find the equation for the line with undefined slope and passing through the point (-1,-2). what do i need to start that off?

what equation do i use to find the slope-intercept?

whats the point-slope form?

1. Reiny

any vertical line has an undefined slope and always has the form x = c, where c is a constant.
All you need is a point, then simply state it as x = 'the x of the given point'

so for your first one : x = 7
for the second x = -1

slope-intercept form looks like this
y = mx + b, where m is the slope and b is the y-intercept

e.g. y = 4x + 9
the slope is 4 and the y-intercept is 9

the point-slope form is one of the best ways to find the equation of a straight line, given the slope and a point

e.g. given the point (5,-3) and slope of 2/3, find the equation

y - (-3) = (2/3)(x - 5)
3(y+3) = 2(x-5)
3y + 3 = 2x - 10

you can now re-arrange it to end up with any version they ask for.

2. Reiny

my last line should have been

3y + 9 = 2x - 10

## Similar Questions

1. ### Algebra...

Write the equation of a vertical line passing through the point (8,-4). Graph x=8 and see if that is what you want. I don't understand?
2. ### Algebra

I'm suppose to write an equation with the following information: Line passes through (2,-6) and is parallel to x=8 I know i must use the slope point form the problem is that since x=8 I don not know which is the slope. Please help …
3. ### algebra

Write the equation of the line with x-intercept (–8, 0) and undefined slope. would this by y=-8x?
4. ### algebra

Write the equation of the line that passes through point (5, 4) with a slope of 0. would this be x=5 then?
5. ### Algebra

Can someone check my answers? 1. Write the equation of the line that passes through point (–2, 3) with a slope of –4. Answer: y = -4x - 5 2. Find the slope and y-intercept. x = –8 Answer: Slope: undefined; y-intercept: none 3.
6. ### math

i have more than one question so if u no any of the answers please tell me 1.) write the point-slope form of the equation of the line with slope -2 passing through the point ( -5, -9). 2.) write the point-slope form of an equation …
7. ### ALG 2!!!

Write an equation of a line with an undefined slope and passing through the point (-2,4). Hint: To answer this question, consider the type of line that has an undefined slope. Then write an equation of that line using the values in …
8. ### geometry

I would love for someone to check my work on the seven problems that I did. I would be eternally grateful. I am going to list my problems and answers. Even if you only want to check one of them, that would be great. 1. Write an equation …
9. ### Math

What is the y-intercept of y = 2/3x + 2? I have to write it out but how?
10. ### Math please.

What is the y-intercept of y = 2/3x + 2? I have to write it out but how?

More Similar Questions