Complete ordered pairs for the equation and then graph the equation 3x+5y=15

Question

Complete ordered pairs for the equation and then graph the equation

3x+5y=15

Answer 1

Hi Winnie!

There are a couple very easy ordered pairs

you can use for this problem - the x-intercept

and the y-intercept.

The x-intercept is where y is 0.

3x + 5(0) = 15

3x + 0 = 15

3x = 15

-- -- divide both sides by 3

3 3

x = 5 so, (5,0) is one point

The y-intercept is where x is 0.

3(0) + 5y = 15

0 + 5y = 15

5y = 15

-- -- divide both sides by 5

5 5

y = 3 so (0,3) is another point

Plot the two points (5,0) and (0,3)

Answer 2

3x+5y=15 can be rewritten as 5y=15-3x by subtracting 3x from both sides. Now, dividing our current equation by 5, we get y = (15-3x)/5 = 3-(3/5)x. So y= 3-(3/5)x. From here, you can just plug in values for x and get the corresponding values of x to graph your equation. For example, plug in x=5 and we get y=3-(3/5)*5 = 3-3=0 so this ordered pair would be (5,0). For another example, we can plug in x=0 and we get y=3-(3/5)*0 = 3, so this ordered pair would be (0,3). Do this for a couple more points, connect your points and you'll have a graph of your line!