Rate of change is the slope.
6x - 7y = 21
Convert to slope-intercept form(y = mx + b):
Subtract 6x to both sides:
-7y = -6x + 21
Divide -7 to both sides:
y = 6/7x - 3
Now it's in the form of y = mx + b, where 'm' is the slope. So the slope here is 6/7.
y = 2x - 2
This is already in slope-intercept form, so the slope here is 2.
For function C, take any two points and plug them into the slope equation.
m = y2-y1/x2-x1
(2, 7)
(3, 1)
m = (1 - 7)/(3 - 2)
m = -6/1
m = -6
So the slope of function C is -6.
(1, 2) and (-1, -4)
m = y2-y1/x2-x1
m = (-4 - 2)(/(-1 - 1)
m = -6/-2
m = 3
So function D has the highest rate of change.
*** Function C and D information based on the comments below ***