When 18 boys Joined a group of y students, the Ratio of boys to girls in the group became 4:5. Write an algebraic expression for the number of girls in terms of y.
Boys + Girls = y ( B + 18 ) : G = 4 : 5 5 ( B + 18 ) = 4 g 5 B + 90 = 4 G 5 B = 4 G - 90 / : 5 B = 4/5 G - 18 Then: 4/5 G - 18 + G = y 9/5 G = y + 18 / * 5/9 G = 5 * ( y + 18 ) / 9 Answer: Number of girls in terms of y is: G = 5/9 y + 10
