The correct answer is 54.3.
Let w = cos(x)
The given equation turns into -5w^2 + 4w + 1 = 0. Use the quadratic formula to find that the two solutions, in terms of w, are:
The solution w = 1 leads to cos(x) = 1 which then becomes x = 0, x = 2pi, x = 4pi, etc. The general way to write this is x = 2pi*n where n is any integer. These angles are in radian mode.
The solution w = -0.2 leads to cos(x) = -0.2 which becomes x = arccos(-0.2) = 1.77215 approximately assuming your teacher wants the angle in radian mode. Unfortunately, I don't know the exact value of x here. There may not be an exact value, or finding this exact value may be well beyond the scope of this course.
Answer:
5/8
Step-by-step explanation:
The answer is 5/8 because 4*5 equals 20 and 4*8 equals 32. Therefore, you have to do the same thing you do to the numerator to the denominator. In addition, you I divided 20 by 4 which is 5 and 32 divided by 4 is 8. So, it is 5/8.