I am preparing a unit on operations with algebraic fractions; But, particularly addition/subtraction of algebraic fraction such as
$$\frac{3}{b} + \frac{2}{a} ; \frac{x+1}{3}- \frac{2x+3}{4}; \frac{2}{x+1}+ \frac{2+x}{x+4} + \frac{x}{2x}$$
I am researching on realistic word problem for a performance assessment related to those for a student level equivalent of US middle school or 1st year high school.
I was thinking: considering that 5 girls in the class like basketball and 3 boys like basketball, evaluate the fraction of students who like basketball in the class if we have
Situation 1: 10 girls and 15 boys
Situation 2: x girls and 10 boys
Situation 3: x girls and 3x boys
Situation 4: there are twice more boys than girls
Situation 5: we have 10 more girls than boys
What could be other interesting word problem, situation that could involve the addition or subtraction of algebraic fraction? Any other suggestion greatly appreciated