Question

[4.06] What is the equation of the line that passes through the points (-2, 1) and (1, 10)?

3x - y = -7

3x - y = -5

3x - y = 5

x + 3y = -5

Answer 1

Graph it @ https://www.desmos.com/calculator

Answer 2

Copy & Paste all 4 equations in seperate boxes on the left. Then see which one crosses both points (-2, 1) and (1, 10).

Answer 3

*separate

Answer 4

I've already found the answer.

Answer 5

first we find the slope
slope(m) = (y2 - y1) / (x2 - x1)
(-2,1) x1 = -2 and y1 = 1
(1,10) x2 = 1 and y2 = 10
now we sub
slope(m) = (10 - 1) / (1 - (-2)
slope(m) = 9/3
slope(m) = 3

now we use y = mx + b
slope(m) = 3
you can use either of your sets of points
(1,10) x = 1 and y = 10
now we sub
10 = 3(1) + b
10 = 3 + b
10 - 3 = b
7 = b

our equation is : y = 3x + 7 but we need it in standard form
Ax + By = C

y = 3x + 7 -- subtract 3x from both sides
-3x + y = 7 -- multiply by -1 to make x positive
3x - y = -7

Answer 6

any questions at all ?

Answer 7

thank you texaschic, can you help me on one more

Answer 8

what ya got ?

Answer 9

@texaschic101

Answer 10

In y = mx + b form, the m is the slope and the b is the y intercept

3x + 2y = 12 ---- subtract 3x from both sides
3x - 3x + 2y = -3x + 12
2y = -3x + 12 -- divide both sides by 2
y = -3/2x + 6
slope(m) = -3/2, and y intercept (b) = 6 or (0,6)

Answer 11

ok, which answer is it?

Answer 12

first one

Answer 13

thanksssssss

Answer 14

sure thing :)