Answer:

Step-by-step explanation:
Suppose the electrician spends t hours at the house working.
Amount charged for every house call by electrician = $50
The electrician earned a total of $400 for a 5 hour job.
Also, C denotes total cost of the electrician's services.
So, the equation for C in terms of t is given below.

Here, 
Option C, y = 1/2 x -2 is the correct answer
Answer:
60%
Step-by-step explanation:
we know that
the price per share of a stock decreased from $90 per share to $36 per share
In this problem
$90 represent the 100%
so
using proportion
Find out what percentage represent the difference of ($90-$36)
($90-$36)=$54
Let
x ----> the percentage of the difference

Answer: $15.20
Step-by-step explanation: He earned $15.20. Just multiply the 2.00x4 and the 2.40x3
Answer:
D) 3x^2 - 12
Step-by-step explanation:
Using PEMDAS;
There is no need to evaluate the part of the equation (x^2 - 8) because is no need to, as it is already in its simplest form.
We must evaluate the part of the equation continuing with, "- (-2x^2+4)," as it is not in its simplest form.
Evaluating "- (-2x^2+4)":
Step 1: Distributing the negative
Once distributing the negative symbol amongst the values within the parenthesis according to PEMDAS, we get "2x^2 - 4" as the product.
Step 2: Consider the rest of the equation to evaluate
Since the part of the equation is still in play here as it is a part of the original equation to be solved, we must evaluate it as a whole to get the final answer.
Thus,
x^2 -8 + 2x^2 - 4 = ___
*we can remove the parenthesis as it has no purpose, since it makes no difference.
Evaluating for the answer, we get,
x^2+2x^2 + (-8 - 4) = 3x^2 - 12
Hence, the answer is D) 3x^2 - 12.