Answer: none of them is right, did you meant maximum 4 and minimum 2?
Step-by-step explanation: cos x gets values between 1 and -1.
If you add 3 you get values between 4 and 2.
How the quadratic formula works:
For any quadratic equation ax² + bx + c = 0, the solution is

.
In the case of our equation 7x² - x = 7, first we need to subtract 7 from each side so that we have 0 on the right.
7x² - x - 7 = 0
Identify the values of a, b, and c.
a = 7, b = -1, and c = -7.
Plug these into our quadratic formula and solve.

There are two values for x: (1+√197)/14 and (1-√197)/14.
The approximate values for these are 1.073976 and -0.931119.
it will be 451/100 as an improper fraction! :)
Answer:
Step-by-step explanation:
Side-angle-side.
X = 36/5
Or x = 7.2
21 + x = 6x - 15
21 = 6x - 15 - x
21 = 5x - 15
21 + 15 = 5x
36 = 5x
36/5 = x