64, -48, 36, -27
which formula describes the sequence?

The formula would be

T(n) = 64 (-3/4)^n, n=0,1,2,...

or sometimes

T(n) = T(n-1)(-3/4),     T(0) =64, n=0,1,2,...

Step-by-step explanation:

The common ratio is -3/4, i.e.

(-3/4) * 64 = -48

(-3/4) * 48 = 36

(-3/4) * 36 = -27

...

The formula would be

T(n) = 64 (-3/4)^n, n=0,1,2,...

or sometimes

T(n) = T(n-1)(-3/4),     T(0) =64, n=0,1,2,...

Note: Would have been easier if the choices were supplied.

x² + 3x + 7 = 0       [ax² + bx + c]

a = 1

b = 3

c = 7

quadratic formula:

    (+/- is this ±)

plug in the numbers into the variables

your answer is a