For this case we propose the following expression:
x: Variable representing the unit rate of each soda
So:
Thus, 0.42 dollars is paid for each soda.
Answer:
the unit rate of each soda is 
Bobbie: x comic books
Kenny: 9 more comic books than Bobbie: x + 9
Together: 95 comic books
To write the equation that could be used to find the number of comic books they each have, we have to put it together:
x + (x + 9) = 95
x + x + 9 = 95
2 * x = 95 - 9
2 * x = 86 /2
x = 86 / 2
x = 43
Result: Bobbie has 43 comic books, Kenny has 52 comic books (43 + 9).
adam still has 23/45 of his original collection
(70+71+72+x)/4 ≥ 73
(213+x)/4 ≥ 73
213+x ≥ 73*4
213+x ≥ 292
-213 -213
x ≥79
Check:
(70+71+72+80)/4
292/4
73.25
Your Answer:
x ≥ 79
