Question

Given the function y = 5x – 7, how does the y-value change as x increases by 1?

Answer 1

pick any x value you want

Answer 2

tell me which x value you picked

Answer 3

The y-value decreases by 7?

Answer 4

just pick any number you want and I'll show you how to find the answer

Answer 5

Ok how about we pick the number 0, sound good?

Answer 6

yah

Answer 7

ok when x = 0


y = 5x – 7


y = 5(0) – 7 ... plug in x = 0


y = 0 - 7


y = -7


So when x = 0, y is y = -7

Answer 8

So keep these two values in mind: x = 0 and y = -7

Answer 9

Now bump x up by 1 to get x = 1 and repeat


y = 5x – 7


y = 5(1) – 7 ... plug in x = 1


y = 5 - 7


y = -2


So when x = 1, y is y = -2

Answer 10

Notice how when x goes from 0 to 1, y changes from -7 to -2

so as x goes up by 1, y goes up by 5 (the distance from -7 to -2 is 5 units)

Answer 11

this is exactly what the slope is saying

the slope is rise over run = 5/1 = (change in y of 5 units)/(change in x of 1 unit)

Answer 12

ooooh so the y value increases by 5?

Answer 13

exactly

this is probably more evident if you use x values such as x = 3 and x = 4


When x = 3, y is...


y = 5x – 7


y = 5(3) – 7 ... plug in x = 3


y = 15 - 7


y = 8


So when x = 3, y is y = 8


When x = 4, y is...


y = 5x – 7


y = 5(4) – 7 ... plug in x = 4


y = 20 - 7


y = 13


So when x = 4, y is y = 13


The change from 8 to 13 is also 5 units, so that just further verifies the answer

Answer 14

okayy thank you

Answer 15

yw