The average age of a groom in a wedding for the given age of the bride can be approximated by g(x)= -.0048x^2 +1.44x -3.316, 20≤x≤55, where y is the age of the groom and x is the age of the bride. For which age of the bride is the average age of the groom 30?

2 answers

0 = -.0048 x^2 + 1.44 x - 3.316-30

.0048 x^2 -1.44 x + 33.316 = 0

x^2 - 300 x + 6941 = 0

x = [ 300 +/-sqrt(90,000 -27,764) ] /2

x = [300 +/- sqrt(62,236) ]/2

x = [ 300 +/- 249 ] / 2

x = 25.26 ignoring the unrealisic solution
perfect thanks Damon!