So first you would combine the like-terms so you get:

and combine the second like-terms:

now you only have a two step equation and you continue by doing the reciprocal and you add the -1/5 to the 24.8 where you get:
7/9x=24.6
then because the 7/9 is being multiplied by the x and your trying to isolate it you divide it by the 7/9 on both sides and you'll end up getting
x=31.628571429....
The fraction 36/180 can be recuced to 1/5 because 36 divided by 36 is 1 and 180 divided by 36 is 5 hope it helped :)
Step-by-step explanation:
-2x³ + 14x² + 120x
= -2x(x² - 7x - 60)
= -2x(x - 12)(x + 5).
The other 2 dimensions are -2x and (x + 5).
When using a graphing calculator to maximise the volume of the prism, we get x = 7.378. However this value is not reasonable as it makes -2x and (x - 12) negative, which are the sides of the prism.
Answer:
a) For this case we can use the fact that 
And for this case since we ar einterested on
and we know that the if we are below the y axis the sine would be negative then:

b) From definition we can use the fact that
and we got this:

We can use the notabl angle
and we know that :

Then we know that
correspond to 225 degrees and that correspond to the III quadrant, and we know that the sine and cosine are negative on this quadrant. So then we have this:

Step-by-step explanation:
For this case we can use the notable angls given on the picture attached.
Part a
For this case we can use the fact that 
And for this case since we ar einterested on
and we know that the if we are below the y axis the sine would be negative then:

Part b
From definition we can use the fact that
and we got this:

We can use the notabl angle
and we know that :

Then we know that
correspond to 225 degrees and that correspond to the III quadrant, and we know that the sine and cosine are negative on this quadrant. So then we have this:
