Subtract the 2 equations
7x+2y=-19
- -x+2y = 21
--------------------------
8x +0y=-2
x= -1/4
Answer:
First image attached
The error was done in Step E, because student did not multiply
by the negative sign in numerator. Step E must be
.
Second image attached
The error was done in Step C, because the student omitted the
of the algebraic identity
. Step C must be 
Step-by-step explanation:
First image attached
The error was done in Step E, because student did not multiply
by the negative sign in numerator. The real numerator in Step E should be:

Hence, Step E must be
.
Second image attached
The error was done in Step C, because the student omitted the
of the algebraic identity
. Step C must be 
And further steps are described below:
Step D

Which according to the Quadratic Formula, represents a polynomial with complex roots. That is: (
,
,
)


(Conjugated complex roots)
Step E

Step F

Answer:
$27,643
Step-by-step explanation:
The net present value is the present value of after tax cash flows from an investment less the amount invested.
The formula for the NPV can be found in the attached image.
The NPV can be found using a financial calculator:
The cash flow for year zero = $-36,000
Cash flow from year one to three = $19,000
Cash flow for year four =$19,000 + $5,000 = $24,000
I = 10%
NPV = $27,643
I hope my answer helps you
Taking the same test right now....I think the answer is 4.5. Hope that helps!
Let x be the number.
Set up an equation:
2x - 2/3x = 20
Simplify:
1 1/3x = 20
Divide both sides by 1 1/3
X = 15
The number is 15