Find all solutions of the equation 2 cosine squared theta plus 9 cosine theta minus 5 equals 0, in the interval [0,2pi).

Two possible answers are:

2/20 gallons per minute and 3/30 gallons per minute.

Explanation:

To find equivalent ratios, we are finding equivalent fractions.  To do this, we would multiply the numerator and denominator of the original fraction, 1/10, by the same constant.

(1*2)/(10*2) = 2/20 and (1*3)/(10*3) = 3/30.