Amachine makes 300 boxes in 15 minutes. which expression equals the unit rate in boxes per hour

the rate of change is 25

we can set up an equation to find the girls' ages. the equation is         28=0.5x-5+x. (comment if you need me to explain how i got this equation.) so, you add x and 0.5x to get 1.5x and add 5 to each side. your new equation is 33=1.5x. now divide both sides of the equation by 1.5 to get 22=x. because x is mary's age, to find jasmine's age we subtract mary's age from 28. we find that mary is 22 years old and jasmine is 6 years old.