Question

Find the slope-intercept form of the equation that goes through these two points-
(1, 20) (8, 4.5)
Can someone help me?

Answer 1

Do you have a graph

Answer 2

it helps

Answer 3

Do you know the slope equation?

Answer 4

Just plug in the x and y coordinates in the equation and you will get the slope

Answer 5

You need the equation, and a chart if you want to make it easy

Answer 6

Once you know the slope you can plug in one of the coordinates in the slope intercept equation (y=mx+b) and you will get the y intercept

Answer 7

abby? :O

Answer 8

hope this helps!

Answer 9

I do not have a graph... what does the slope equation look like?

Answer 10

Hard to do without one

Answer 11

oh ok @benlindquist

Answer 12

We want an equation of the form y=mx+c, so we need to find m (the gradient) and c (the y intercept). Given our two points, we can find the gradient (the change in y divided by the change in x):
\[m=\dfrac{20-4.5}{1-8}=\dfrac{15.5}{-7}=-\dfrac{31}{14}\]Now we have m, we can use this and either of our coordinates to find c.\[y=mx+c=-\dfrac{31}{14}x+c\]Let's use (1,20):\[20=-\dfrac{31}{14}\times1+c\]\[c=20+\dfrac{31}{14}=\dfrac{311}{14}\]Giving our answer:\[y=-\dfrac{31}{14} x+\dfrac{311}{14}\]

Answer 13

\[y ^{2}-y ^{1}\div x ^{2}-x ^{1}\]

Answer 14

thats the slope equation

Answer 15

Ok thank you @Smartanne

Answer 16

@Smartanne, you should really use subscript for variables otherwise it looks like you're raising it to that power.\[\frac{y_2-y_1}{x_2-x_1}\]

Answer 17

@tom982 In the answer you gave me those are fractions right?

Answer 18

Yes, that's in the line where I worked out m, the gradient.

Answer 19

ok i'll do that next time @tom982