Answer:
7x+12 because there is 8x then you subtract 1x which 'll equal 7x and add the 12
The answer is D because I took the test
Slope-intercept form follows the formula: y=mx+ b
To find the slope intercept form of those, you need to isolate y
For example, x + y + 3 = 0. Subtract 3 and x to get y=-x-3 and that is your slope intercept form! Simple as that :)
If this is supposed to be

Then this can simply be reduced to

by the double angle formula for cosine