How to write equations for lines..?

Question

The question is "for each, write an equation for the line satisfying the given condition."

I don't get how you would do this.

For example, for one of them, it says that "slope= -4 and passes through (1,1)"

What does this mean? How do you convert these into equations?

Answer 1

There are two basic ways to write an equation.  

They are:  Ax + By + C=0 and  y= mx+b, where m is the slope and b is the y-intercept.   CLEARLY (I hope you realize), the second way is the one you want.   So.....

y = -4x + b.  Now you have to find b.  So you can substitute in the point x=1 when y=1 and solve for b.  

                

Answer 2

follow the format y= mx+b, m is your slope, then plug in 1 for y and one for x, solve for b, then that's your equation. so it would be y= -4x + 5

Answer 3

To write it into an equation u would apply (y-y1)=m(x-x1)

y1 would means coordinate for y which is 1 and x1 means coordinate for x which is also 1, and "m" is the gradient of the line aka slope which is -4

So, the equation can be written as

y-1=-4(x-1), by expanding it u get

y-1 = -4x +4  by expressing y in terms of x u get

y = -4x +5

good day

Answer 4

the equation of a line is always in the form y=mx+b

y=the y value

m=the slope

x=the x value

b=the y-intercept

so it would be

1=-4(1)+b

then solve from there if you need to

1=-4+b(distribute)

5=b(add -4 to both sides)

Answer 5

The formula you are using is y=mx+b

so you plug in the points for x and y and the slop for m

1=-4(1)+b

1=-4+B

Then you must solve for B

1= -4+b

Add 4 to both sides

5=B

So then your final equation is

y=-4x+5  

Answer 6

see these site dear...

http://www.mathwords.com/p/point_slope_e...

http://www.purplemath.com/modules/strtln...

http://www.freemathhelp.com/point-slope....

http://www.algebra-online.com/equations-...

you can see examples too...

--regards--

Answer 7

Find the slope and write the equation in the form y = mx + b

m is the slope and b is the y-intercept

y-y1 = m(x-x1)

y-1 = -4(x-1)

y-1 = -4x + 4

y = -4x + 5

Answer 8

find slope

(y-y1)/(x-x1)

use point slope

(y-y1)=mx-x1)

then put it into y =m(slope is always m)

y=mx+b (b is the y intercept)

ur problem would look like this...

y-1=(-4)(x-1)

y-1=-4x+4

y=-4x+5