Answer:
x= 19/4
Step-by-step explanation:
<span>D-21.4=87.9 \ solve for D
add 21.4 to both sides
</span><span>D - 21.4 +21.4 =87.9 + 21.4
simplify
D = 109.3</span>
Y = 2x + 4 and y = 3x + 1
Therefore, 2x + 4 = 3x + 1
Answer:

Step-by-step explanation:
We are given the following in the question:
Controller cost = $135
System cost = $2.50 per foot of pipeline
The total cost depends upon the length of Pole.
Let the system requires F feet of pipeline.
Total cost will be given by the equation:

is the required expression for total cost
F: feet of pipeline required
c(F): Total cost of installation