Would 15 miles per gallon be a unit rate??

Yes, 15 miles per gallon would be a unit rate.  

A unit rate is essentially a situation where the quantity is written with a 1 as the denominator (A unit rate is y over x, when x = 1).

a is the correct

answer:   x = 3 + √11     and     x = 3 - √11

step-by-step explanation:

x² - 6x + 9 = 11

(x - 3)² = 11

x - 3 = ±√11

    x = 3 ± √11

x = 3 + √11     and     x = 3 - √11