Answer:

Step-by-step explanation:
Let use the following trigonometric identities:

Then, the equation is simplified by substituting its components:





The answer is D, here’s why:
You know the slope-intercept form is y=mx+b
mx being the slope and b being the y-intercept.
y=-4/7x + 9 is already in that form.
A is not the answer because the y is supposed to be by itself.
B is not the answer because again, the y is not by itself.
C is not the answer because the y is also not by itself.
In the slope-intercept form, the y must be by itself and the slope (mx) and the y-intercept must be on the other side.
Hope this helps.
slope = rise over run = y/x
A (-1,3) slope = 3/-1 = -3
B (1,2) slope = 2/1 = 2
C (-3,-1) slope = -1/-3 = 1/3
2 lines need to be negative reciprocals in order to be a right triangle
negative reciprocal of -3 is 1/3
so this is a right triangle
D, you have to factor 3 out of 6x squared
No offense but the question dosen't make sense