Find how many numbers are divisible by two and three, then place that number above the total number of items in the set as a fraction. Like this:
He need to earn 48
Inequality : 80-32=x
3/4 + 1/2
multiply 1/2 denominator and numerator by 2 to match 3/4
= 3/4 + 2/4 = 5/4 (copy same denominator add numerator)
2/6 + 1/3
divide 2/6 denominator and numerator by 2 to match 1/3
= 1/3 + 1/3 = 2/3 (copy same denominator add numerator)
5/9 + 2/3
multiply 2/3 denominator and numerator by 3 to match 5/9
= 5/9 + 6/9 = 11/9 (copy same denominator add numerator)
6/9 -1/5
cross multiply 6x5 - 1x9 for numerator
for denominator multiply 9x5
=30/45 - 9/45= 21/45
divide num and den by 3
=7/15
5/8-1/3
cross multiply 5x3-1x8 for numerator
multiply 8x3 for denominator
= 15/24 -8/24 =7/24
