Dolbear's Law Question Edited

Question

Algebra question I'm stuck on. I know how to solve for "T" when asked, however I can't seem to figure out how to write the algebraic expression for "N" in order to solve.

Dolbear's Law states the relationship between the rate at which snowy tree crickets chirp and the air temp of their environment. The formula is: T=50+N-40/4 where T is a temperature in degrees Fahrenheit and N is a number of chirps per minute. If T=58 degrees, find the number of chirps per minute.

The answer is:72 Please show me the steps to solve this algebraic expression.

How do I solve for "N" ?

Thank you!

Answer 1

Dolbear's Law:

     T_F = 50 + (N₆₀-40) / 4                  [Remember PEMDAS !!]

 

 

     N₆₀ = 4T_F - 160           [multiply by 4; subtract 160 to both sides]

     N₆₀ = 4*58 - 160             [insert °F]

     N₆₀ = 72            72 chirps per minute (N₆₀ means number in 60 seconds) at 58 °F

 

 

Check: Does 58 = 50 + (72-40)/4 ?

 

  58 = 50 + 32/4 ?

  58 = 50 + 8

  58 = 58 ?yes