Question

Which is the equation of the line?




http://static.k12.com/calms_media/media/1299500_1300000/1299544/1/adb96b45350fd42ac9bf15e721fcb1840fbe25b0/143713.jpg

A.
5x + 3y = 15

B.
5x – 3y = 15

C.
–5x + 3y = 15

D.
–5x – 3y = –15

Answer 1

The x- and y-intercepts are clear and easy to read in the illustration. Please, would you identify these intercepts?

Answer 2

x= -3 and y=5 @mathmale

Answer 3

Yes, or (-3,0) and (0,50. From these 2 points we need to obtain the slope of this line. Do you know how to do that? If so...


m = ?

Answer 4

i dont know how @mathmale

Answer 5

I'm helping several students at once, so am a bit short on time. I will help you to finish this entire problem, but first, I ask you to please look up the equation for 'SLOPE OF A STRAIGHT LINE." We'll need it.

Answer 6

yeah sure m ( the slope) = Y2-Y1/X2-X1

IN OUR CASE we have the intercept on the axis in two points

P1(-3,0)
P2 (0,5)

WHICH lead us to :

\[m =\frac{ 5-0 }{ 0-(-3) } =?\]

Answer 7

itsbribro: I was hoping you'd Google "slope of a straight line," as you'd immediately find the formula that you need. roc_mit knows that formula and is showing you how to use it. you will need to know it later on.

Answer 8

Nice work, both of you! @itsbribro: What do you think the next step should be? Review the original question.

Answer 9

good, youre right, now we are going to find the y- intercept (b), untill now we have

y=mx + b

m and the variables x and y

Answer 10

no m = the increment of y/ the increment x

Answer 11

x is the indepent variable, that means you can plug as many values as you want

Answer 12

y is the in dependent variable, that means you can find the value of y each time you plug a value in x

Answer 13

you were right with the slope m =5/3

Answer 14

y = 5/3x + b

Answer 15

now in order to find the y-intercept (b) you have to assign for x the value 0

Answer 16

\[y=\frac{ 5 }{ 3 }(0) + b\]

Answer 17

so that means find the poin where x = 0 and y =b, in other words (0,b)

Answer 18

@itsbribro where the line cuts the y- axis at what point makes that ?

Answer 19

b = 5

y = (5/3)x + 5 expressed in other way, would be ?

Answer 20

3y = 5x + 15