No13.
Answer:
Cos(x+x)=cosx*cosx-sinx*sinx
=cos2(x)-sin2(x)
=(cosx+sinx)(cosx-sinx)
Answer:
(−3b4)2
−12
b−9
=
−3
4
b8
b9
=
−3
4b
Step-by-step explanation:
Step-by-step explanation:

By calculator
8 = 4 + 4
8 * 3 = (4 + 4) * 3 = (4*3) + (4*3) = 12 + 12 = 24
Answer:
18:5
Step-by-step explanation:
There, hope it helps!