Answer:
casey's age is 7
Step-by-step explanation:
if his sister is 3 times as old as he is then she is older therefore you would devide.
21/3=7
X+(x+1)+(x+2)+(x+3)+(x+4)+(x+5)=393
6x+15=393
6x=393-15
6x=378
x=63
third one is 63+2=65
Answer:
-2/5 -4/3 p and -4/3p+ (-2/5)