18 straws because 72 divided by 4 is 18 that is an example of summary number modeling.
Answer:
17.30 dollars
Step-by-step explanation:
Given that Payton and James mow the lawns.
They do this during summer.
The amount they spend are:
Gas cost = 3.50
Leaf bags = 1.20
Add these to get total costs
Total cost = 4.70
Charge they get per lawn = 22.00
Profit = Revenue - cost
Here revenue per lawn = 22 and cost per lawn = 4.70
Hence profit = 22-4.70 = 17.30 dollars.
Answer is they make 17.30 dollars per lawn.
Step-by-step explanation:
The question is wrong. The correct equation is :

We know that the equation gives the relation between temperature readings in Celsius and Fahrenheit.
Therefore, giving that we know the value in Fahrenheit ''F'' we can find the reading in Celsius ''C''. This define a function C(F) that depends of the variable ''F''.
So for the incise (a) we answer Yes, C is a function of F.
For (b) we need to find the mathematical domain of this function. Giving that we haven't got any mathematical restriction, the mathematical domain of the function are all real numbers.
Dom (C) = ( - ∞ , + ∞)
For (c) we know that the water in liquid state and at normal atmospheric pressure exists between 0 and 100 Celsius.
Therefore the range will be
Rang (C) = (0,100)
Now, we need to find the domain for this range. We do this by equaliting and finding the value for the variable ''F'' :
For C = 0 :
⇒ 
And for C = 100 :
⇒ 
Therefore, the domain as relating temperatures of water in its liquid state is
Dom (C) = (32,212)
For (d) we only need to replace in the equation by
and find the value of C ⇒
⇒

≅ 21.67
C(71) = 21.67 °C
We have the formula tan( a- b ) = ( tan a - tan b ) / ( 1 + tan a· tan b );
We use the formula (sin x)^2 + (cos x)^2 = 1;
Because sin a = 4/5 we have cos a = 3/5; then tan a = sin a / cos a = 4 / 3;
Because sin b = 5 / 13 we have cos b = 12 / 13; then tan b = sin b / cos b = 5 /12;
Finally, tan ( a - b ) = ( 4 / 3 - 5 / 12 ) / ( 1 + (4 / 3)·( 5 / 12 ) ) = ( 9 / 12 ) / ( 1 + 5 / 9 ) = ( 3 / 4 ) / ( 14 / 9 ) = ( 3 / 4 )·( 9 / 14 ) = 27 / 56.