Question

4.06]Which equation represents the line passing through the points (1, 4) and (−2, 13)?

3x + y = 7

3x − y = 7

x − 3y = 7

x + 3y = 7

Answer 1

Take a general equation of a line: y=ax+b and substiute x and y with respectively x and y coordinates of your two points - you'll have a system of two equations and when you solve them, you will get your a and b.

Answer 2

they don't give you a graph and i forgot how to do that correctly. it's been a long time since i've done point slope stuff. which i loved

Answer 3

Ok, so again: you have your line. It passes through those two points. Let's subsitute general x and y by specific x and y coodinates of those two points.
y = ax+b gives us:
4 = 1x + b
13 = -2x + b. Do you see where that came from? Then you have two equations and you can solve for a and b, so you'll get numerical values of them.

Answer 4

If you don't understand, tell me in which part I wasn't clear.

Answer 5

i get it. so whats the answer? i don't have any graph paper to do this right now

Answer 6

You don't need to graph anything. Just solve this system of linear equations. Do you know how to do that?

Answer 7

oh yeah, i hate them though

Answer 8

ok so i got answer c is that right?

Answer 9

Well, if you solve them, you get a=-3 (it was supposed to be a, not an x, sorry) and b=7. So y=-3x+7, then y + 3x = 7 and that's the answer.

Answer 10

ohh i see thanks

Answer 11

Sure. :)