I assume that if we write the equation in its mathematical form it will appear like this:
T = 50 + (N - 40)/4
Substituting the value of T given,
58 = 50 + (N-40)/4
The value of N from the generated equation above is equal to 72. Therefore, the Snowy Tree Crickets chirp 72 times per minute at a temperature of 58°F.
Answer:

Step-by-step explanation:
Area of a Circle: 
The r is the length of the radius of the circle
The radius of the shown circle is 9 m


Combining the operations
The allowed operations are:
Add the same amount to both sides (either x's or ones)
Subtract the same amount from both sides (either x's or ones)
Multiply both sides by the same number (but not by zero)
Divide both sides by the same number (but not by zero)
(There are others, too, but they are not needed in simple equations.)
The goal is to FIRST add and subtract until we have ONLY x's (blocks) on one side and ONLY ones (circles) on the other. Then, if you have more than one block, you need to divide so as to arrive to the situation with only one block on the one side, which is the solved equation!
Answer:
The perpendicular line 4x − 5y = 20 has a slope of 4/5 and as such, the slope of the required line = -5/4
(y - 3)/(x + 4) = -5/4 simplify to get the required equation: 5x + 4y + 8 = 0