Did I do this equation correctly?Please help!?

Question

Find the slope of the line that passes through the following points using the slope formula:(show all work)

(2,4) and (6,12)

so I did y2-y1/x2-x1

12-4/6-2 = 8/4= 2

Then I substituted into y=mx+b for m,x,and y.I used one of the points given.I chose (2,4).

y=mx+b

m=2

x=2

y=4

4=(2)(2)+b

4=4+b

Subtracted 4 from both sides.

And that gave me 0= b

Is this correct?Im having alot of trouble with these problems.

I dont understand what means "find the slope of the line that passes through the following points"?

IF THIS IS NOT CORRECT,CAN SOMEONE PLEASE HELP ME?!

Answer 1

Its correct !i

Answer 2

Your answers are correct.  :)

I must point out that your calculations aren't written correctly.

12-4/6-2 ≠ 2

12-4/6-2 = 9⅓, because division is performed before addition. It should be

(12-4)/(6-2)

Answer 3

You did great .. but you went to far

...

this is all you needed:

so I did y2-y1/x2-x1

12-4/6-2 = 8/4= 2

The answer is "2" .. that is the slope

The second part that you went on to do is calculating the "y intercept" .. or where the line woudl cross the Y axis and that is (for this line) where y = 0 .. just like your proved b = 0

The line will have an equation of y = 2x +0

The answer to the slope question is 2

Answer 4

The first part was already the answer because the slope formula is y2-y1/x2-x1. So the answer is 2. You can check this by graphing the two points and looking at its slope.

Answer 5

Hi there, I've tutored math for 5 years at the college level and I have to say that you have just given me a new way to consider this type of problem!  Your logic works, although typically it is not the way it is taught.  You have your answer right up until the end.  Going your way, b=0 Which gives you the equation y=2x as your answer.

The way this problem is typically solved, you need to first use the slope formula like you did.  m= (y2-y1)/(x2-x1)

You did this correctly getting m=2

You then choose one point and use the slope to substitute into the Point-Slope Formula.  It is named this way because you need a point and the slope in order to use it.

This formula is Y-y1=m(X-x1)

You do NOT substitute for the Capital X or Capital Y, only x1 and y1.

From your problem, you can choose the point (2,4) and the slope m=2

This would give you:

Y-4=2(X-2)          (Distribute the 2 through)

Y-4=2X-4            (Add 4 to both sides)

Y=2x

Hope this helps you!

Answer 6

Absolutely correct. But, you found the equation of the line. You could have just stopped after finding y2-y1/x2-x1.

The slope you found was 2. 2 is m in the equation you have.

y = mx + b is the general equation of a line, known as point slope form, It is not the slope formula.

In this equation, m is hte slope, b is the y-intercept. So you asnwer should be what you got from:

y2-y1/x2-x1, which was 2.

Your work is absolutely correct though, everything is perfect. It's probably that you're just confused between the formulas/variables.

[The answer is 2, and it is gotten by (y2-y1)/(x2-x1)]