how to graph the function y=5x+10

Question

i dont know how to do it... i know 5x makes the y 5 but i dont know what to do with the 10...

Answer 1

You can't talk about graphing until you understand what a function is.  I can tell you don't understand this because you said "I don't know what to do with the 10".

 

y = 5x + 10 expresses y as a FUNCTION of x.  

 

That is, given a value of x I have a formula to get a value for y.    You could also write this function as 

 

f(x) = 5x + 10

 

So when x is 0, then the formula gives the value of y as 5*0+10 which is 10; and when x is 1, the formula gives the value of y as 5*1 + 10 which is 15.  

 

For each value of x, the function formula gives a value of y.  you can make a table:

 

X    Y

0   10

1   15

-1  5

2   20

-2   0

 

 

Then to graph the function, you need to plot these points (0,10), (1,15), (-1,5), (2,20),(-2,10) on  graph paper.

Answer 2

Hi Ali;

y=5x+10

This is in slope-intercept format...

y=mx+b

m is the slope, also known as rise-over-run.  As you already know, this is 5.

b is the y-intercept, the value of y when x=0.  It is the point at which the line crosses the y-axis.  This coordinate is (0,5).

 

Answer 3

This is what you need to do to draw a graph for this function:

 

1. substitute X with a few values and calculate the Y based on the specific value that you substituted X with, e.g.:

 

X=0 => Y = 5*0 + 10 = 10

X=1 => Y = 5*1 + 10 = 15

X=2 => Y = 5*2 + 10 = 20, and so on. Since this is a linear function, it is sufficient to have coordinates for 2 instances and then draw a straight line through those points.

One point will have coordinate X=0 and Y=10 and the other will have X=1 and Y=15

 

Hope this helps.

 

Good luck!