Answer:
D
Step-by-step explanation:
n = 5
an = 176
an = a1*x^(n -1)
a5 = a1 * x^4 = 176
a7 = a1 * x^6 = 704
a7/a6 = a1 * x^6 / a1*x^4 = 704 / 176
Cancel out a1
x^6/x^4 = 704/176 Divide numerator and denominator by 176
x^2 = 4 Take the square root of both sides
x = 2 or - 2
176 = a1 * x^4
176 = a1 * 16
a1 = 11
a1 is going to be 11 whether x is 2 or minus 2.
