<span>The ratio of boys to girls in the class was 4:5. There were 24 people in the class. How many boys? How many girls? ------- 4:5 is the same as 4x:5x where 4x is # of boys and 5x is # of girls. ---- Equation: 4x+5x = 24 9x = 24 x = 24/9
On the added picture you can see that graphs of functions and have two points of intersection. The x-coordinates of these points are the solutions of the equation . Hence, the approximate solutions are x=-1.9 and x=1.6.