1) convert 3/5 to a decimal (show work) 2)convert 3 8/10 to a decimal (show work) 3)convert 5/9 to a decimal (show work)

1) To convert 3/5 to a decimal, we first multiply the numerator and denominator by 2 to obtain 6/10. One tenth is 0.1, so 6/10 is 6 times 0.1, or 0.6. 2) To convert 3 8/10 to a decimal, we see that 3 can be seen as a whole-number decimal, and 8/10 is 8 times 0.1, or 0.8. Adding these, we obtain 3.8. 3) We cannot write 5/9 as a decimal that terminates, but we can approximate 5/9 as a decimal. First, we multiply the numerator and denominator by 111, giving 555/999. Then we say that 999 is approximately 1000, so 555/999 is approximately 555/1000. Since 1/1000 is 0.001, then 555/999 is approximately 555 times 0.001, or 0.555.

Let x be the number of apples 
Let y be the number of oranges 

x+y≤20 
0.24x+0.8y≤12

x≤20-y 

0.24(20-y)+0.8y≤12
4.8-0.24y+0.8y≤12
0.56y≤7.2
y=12.9 (you can choose 12 here, since you can't have a fraction of an orange sold) 

x= 7.14 (again, rounding this off to 7) 

Therefore, Darcy got 12 oranges and 7 apples. 

Hope I helped :)