Select the equation of the line that passes through the point (2, –1) and has slope 3 in point-slope form.

A.
(y – 1) = 3(x + 2)

B.
(y + 1) = 3(x – 2)

C.
(x + 2) = 3(y – 1)

D.
(x – 2) = 3(y + 1)

Question

Select the equation of the line that passes through the point (2, –1) and has slope 3 in point-slope form.
 
 A.
(y – 1) = 3(x + 2)
 
 B.
(y + 1) = 3(x – 2)
 
 C.
(x + 2) = 3(y – 1)
 
 D.
(x – 2) = 3(y + 1)

jim_thompson5910 · Answer

hint: point slope form in general is 

$$\Large y - y_{1} = m(x - x_{1})$$

jim_thompson5910 · Answer

m is the slope 

$\Large (x_{1}, y_{1})$ is the point the line passes through

keeli_grace · Answer

Thank you @jim_thompson5910 
But I don't understand any of that. I am a straight A student except for Algebra.
Do you think that you could explain farther, please?

jim_thompson5910 · Answer

what's the given slope of this line?

keeli_grace · Answer

3?

jim_thompson5910 · Answer

So m = 3

jim_thompson5910 · Answer

We then plug m = 3 into 

$$\Large y - y_{1} = m(x - x_{1})$$

to get

$$\Large y - y_{1} = 3(x - x_{1})$$

jim_thompson5910 · Answer

What is the given point the line passes through?

keeli_grace · Answer

2, -1?

jim_thompson5910 · Answer

(2,-1)

jim_thompson5910 · Answer

So (x1,y1) = (2,-1)

what is x1 equal to?

keeli_grace · Answer

2?

jim_thompson5910 · Answer

x1 = 2

jim_thompson5910 · Answer

plug this into 

$$\Large y - y_{1} = 3(x - x_{1})$$

to get

$$\Large y - y_{1} = 3(x - 2)$$

jim_thompson5910 · Answer

y1 = -1

plug that into 

$$\Large y - y_{1} = 3(x - 2)$$

to get

$$\Large y - y_{1} = 3(x - 2)$$

$$\Large y - (-1) = 3(x - 2)$$

$$\Large y + 1 = 3(x - 2)$$

Notice how the sign changed

keeli_grace · Answer

OH!!!!!!! Thank you so much!!! :)