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

The total cost for the entire life span of the deep fryer is computed below:
Brand P total cost =Purchase price + total electricity cost
= $144+($0.49x8x12x6)
=$426.24
Brand Q total cost =(Purchase price x 3)+ total electricity cost
=( $37.5x3)+($0.75x 8x12x6)
= $544.5
Difference = Brand Q-Brand P
=$544.5-$426.24
=$118.26
Robert will have to choose Brand P because it will be cheaper by $118.26 than Brand Q in their entire lifetime.
Hence, the value of x=8
Mark brainliest please
Hope this helps you
Answer is <span>C. 80
hope that helps
75% are full with 20 seats empty so </span>20 seats empty = 25%
75% * 20 / 25% = 60