Answer:
x = -7
Step-by-step explanation:
f(x) = -2x + 9
f(x) = 23
therefore, f(x) =
-2x + 9 = 23
-2x = 23 - 9
-2x = 14
-x = 14 ÷ 2
-x = 7
x = -7
I'm not sure if that's what you mean, but I assume you might want to know how long did it take to make one lap if someone did 21 laps in 7 minutes.
If so, just divide 7 by 21:
7 ÷ 21 = 0.3333333... (repeating decimal) or 1/3 as a fraction.
It means that one lap took 1/3 of a minute (20 seconds).
If that's not what you meant, please specify the question :)
Answer:
The associative property states that you can add or multiply regardless of how the numbers are grouped. By 'grouped' we mean 'how you use parenthesis'. In other words, if you are adding or multiplying it does not matter where you put the parenthesis. Add some parenthesis any where you like!.
The Commutative property states that order does not matter. Multiplication and addition are commutative.
hope this helps please mark brainliest!