Answer:
200 pairs of sandals
Step-by-step explanation:
Represent the sandals with x and the running shoes with y.
In a typical month:

In April

Required
The number of sandals in a typical month
<u>In a typical month:</u>
If 1 sandal costs 2.50, then x costs 2.50x
If 1 running shoe costs 4, then y costs 4y
The total is:

<u>In April:</u>
If 1 sandal costs 2.50, then 2x costs 5x ---- <em>we used 2x because the pairs is doubled </em>
If 1 running shoe costs 4, then y costs 4y
The total is:

The equations are:


Subtract




3: independent
4: dependent
In simplified form it is 5x+5
Number of comic books Bobbie has - b
95 = (9 + b) + b
Since 95 is the total number of comic books both boys have, it is equal to both boys' books added together. However, since we don't know how many books Kenny has, and only that he has 9 more than Bobbie, we can define that as (9 + b), or nine more than b. Then, we add b again, because (9 + b) is the number of books Kenny has, and if we add that to the number of books Bobbie has, it will equal the total of 95 comic books.
312-170=142
142÷2=71
170+71=241
241+71=312
train A weighs 241 tons