12x15=18(3x+4)
180=54x+72
-72 -72
108=54x
/54 /54
2=x
X=2 the other person is a d0uche for answering like that so I answered instead of them
In step 2 .. because when you multiple by -4 in step 1 , the equation in step 2 will be ( -4y =-16 + 8z)
It is already in identity.
cos (x - y) - cos (x + y) = 2 sin(x) sin (y)
Answer:

Step-by-step explanation:
We can use the FOIL method to expand two multiplied binomials. It states that
. The FOIL method stands for First(first terms) outer(outer terms) inner(inner terms) last(last terms).
So, we can expand our binomials now!
