To solve this question, we can start to set up an equation using what the question is telling us. Since we don't know what the number is, let's make it equal to x.
The phrase "5 times a number" means that we're multiplying our unknown, x, by 5. That is equal to 5x. 9 less than that would be 5x - 9. Since we know that it's equal to -30, we can solve.
5x - 9 = -30
Get all terms with x on one side and the constants on the other
5x - 9 +9 = -30 + 9
Simplify
5x = -21
Now, we can divide both sides by 5 to get our answer of x = -
Question: The area of a square is 324 square inches. What is the length of one side of the square?
The formula for finding area of squares is:
Length x Width
Squares have 4 sides, and all sides measure the same. If the area is 324 square units, that means the length and width are the same.
x X x=x2
X2=324
x squared(x²) is equal to 324. To find x, you have to do the opposite of squaring, which is finding the square root.
x2= 324 —> square root of 324=x
To find x, you have find the square root of 324.
Square root of 324 is 8
The length of one side is 18 inches
Check:
The formula for finding area is:
Length x Width
The length and width gotten was 18. Put that into the formula:
18 x 18
Multiply:
18 x 18= 324
That means the answer is correct. Your answer is 18 inches.
If you have any questions, feel free to ask in the comments! :)
Answer:
36 miles
Step-by-step explanation:
(Imagine a huge triangle on a perfectly open space-- not with streets or houses or cornfields.)
The dimensions of the two sides given are multiples of a classic Pythagorean Triple: 3, 4, 5. 
9 is 3x3, 12 is 3x4 so the remaining side would be 3x5 15
Add those 3 sides to get the total distance, 36 miles.
