249 children and 394 adults swam at the public pool.
Step-by-step explanation:
Number of people swam at pool = 643
Receipts = $1161.50
Cost for one child = $1.50
Cost for one adult = $2.00
Let,
x be the number of children
y be the number of adults
According to given statement;
x+y=643 Eqn 1
1.50x+2.00y = 1161.50 Eqn 2
Multiplying Eqn 1 by 2

Subtracting Eqn 2 from Eqn 3

Dividing both sides by 0.5

Putting x=249 in Eqn 1

249 children and 394 adults swam at the public pool.
Keywords: linear equation, subtraction
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The term "closed" in math means that if you take two items from a set, do some operation, then you'll always get another value in the same set (sometimes you may get the same value as used before). For example, adding two whole numbers leads to another whole number. We therefore say "the set of whole numbers is closed under addition". This applies to integers as well because integers are positive and negative whole numbers. So we can say that integers are closed under addition.
Integers are not closed under division. Take two integers like 2 an 5 and divide: 2/5 = 0.4 which is not an integer. Integers don't have decimal parts.
The set of whole numbers is {0,1,2,3,...} and we can subtract the two values 1 and 2 to get 1-2 = -1. The order matters here. Subtracting a larger value from a smaller leads to a negative. The value -1 is not in the set of whole numbers. So we can say that whole numbers is not closed under subtraction
Finally, the set of irrational numbers is closed under addition. Adding any two irrational numbers leads to another irrational number. For instance, pi+sqrt(2) = 3.142 + 1.414 = 4.556; I'm using rounded decimals as approximate values. An irrational number is one where we cannot write it as a fraction of integers. Contrast that with a rational number in which we can write it as a fraction of integers. Example: 10 = 10/1 is a rational number.
2nd option
Step-by-step explanation:
idk i just guessin
Not sure sorry but you can. Try searching on google or yahoo answers
X - the number of plants in 8 in pots
y - the number of plants in 10 in pots

4 plants in 8 in pots and 2 in 10 in pots.