The average age of the groom at a first marriage for a given age of the bride can be approximated by the model y=-.107x^2+5.68x-48.5, 20<=x<=25. Where y is the age of the groom and x is the age of the bride. For what age of the bride is the average age of the groom 26?

Answer 1

What a silly silly question, anyway....

-.107x^2 + 5.68x - 48.5 = 26
-.107x^2 + 5.68x - 74.5 = 0
times 1000 to get rid of all those decimals

107x^2 - 5680x + 74500 = 0
use the quadratic formula and reject any answer that falls outside the given domain
(I did get a valid answer)