17x/9+19x/12=5

You will have to find the least common denominator for the two fractions so you can add the two fractions. After adding the two fractions you will be able to multiply both sides of the equation by the combined fraction's denominator. Remember that ax+bx=(a+b)x. "a" and "b" will be ordinary numbers you will be able to add. Then divide both sides of the equation by the total of a and b.

there are 18 girl and 12 boys on student council. If two student council member are selected at random, what is the probability that the first member is a boy and the second member is a boy?