What is the equation of the line that passes through the points (−2, 1) and (1, 10)?

Question

anonymous · Answer

In point slope, the equation is$$(y-1) = 3(x+2)$$

anonymous · Answer

Right I understand how do you do it though

anonymous · Answer

IMPORTANT LINE RELATED EQUATIONS TO KNOW AND MEMORIZE

slope formula
m= slope/ gradiant -- same thing
$$m=\frac{y_2-y_1}{x_2-x_1}$$

standard formula
$$Ax+By=C$$

point-slope formula
$$y-y_1=m(x-x_1)$$

slope-intercept formula
b= y-intercept -- in the form of (0,y)

$$y=mx+b$$

anonymous · Answer

first you start off by determining the slope of the line

then you can put it in point slope form and convert it into slope intercept form
or standard form depending on what hte question is asking for

personally i usually write line equations in slope intercept form as the final form

anonymous · Answer

ok but how do you determine the slope

anonymous · Answer

The general formula for finding slope (m) is in his post, but here it is anyway:

$$\frac{ y_2 - y_1 }{ x_2 - x_1 }$$

Or, as I like to say, rise over run (but that's kinda confusing and elementary)

anonymous · Answer

ok so the slope would be 3/9 or 1/3

anonymous · Answer

The slope would be 3.

$$\frac{ 10-1 }{ 1+2 } = \frac{ 9 }{ 3 } = 3$$

anonymous · Answer

right i flipped it

anonymous · Answer

Can anybody help me

anonymous · Answer

A solution calculated with Mathematica 9 is attached.

anonymous · Answer

Thanks so muck robotobey