Answer:
b. y-y1 = m(x-x1)
Step-by-step explanation:
It's a matter of definition. There are perhaps a dozen useful forms of equations for a line. Each has its own name (and use). Here are some of them.
- slope-intercept form: y = mx + b
- point-slope form: y -y1 = m(x -x1)
- two-point form: y = (y2-y1)/(x2-x1)(x -x1) +y1
- intercept form: x/a +y/b = 1
- standard form: ax +by = c
- general form: ax +by +c = 0
Adding y1 to the point-slope form puts it in an alternate form that is useful for getting to slope-intercept form faster: y = m(x -x1) +y1. I use this when asked to write the equation of a line with given slope through a point, with the result in slope-intercept form.
P would equal negative three.
Answer: y =
x + 1
Step-by-step explanation:
First, we will find the slope. The slope of perpendicular lines are negative reciprocals.
In this case, the first slope is 2. The negative of 2 is -2, and the reciprocal of -2 is
.
Now, we will plug in this new slope, the point given, and solve for the <em>b</em>, or the y-intercept.
y = <em>m</em>x + <em>b</em>
(-1) = (
)(4) + <em>b</em>
-1 = -2 + <em>b</em>
1 = <em>b</em>
Lastly, we will write our equation.
y = <em>m</em>x + <em>b</em>
y =
x + 1
The line is y =
x + 1, or y = 1 -
.
Answer:

Step-by-step explanation:
Solve the value of
:

-Combine
and
by subtracting
by
:


-Subtract
on both sides:


-Multiply both sides by
, the reciprocal of
:



Therefore, the value of
is
.