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:
sin θ . tan θ
Step-by-step explanation:
Note : -
sec ( - θ ) = sec θ
Formula / Identity : -
sec θ = 1 / cos θ
sec ( - θ ) - cos θ
= [ 1 / cos θ ] - cos θ
{ LCM = cos θ }
= [ 1 / cos θ ] - [ cos²θ / cos θ ]
= [ 1 - cos²θ ] / cos θ
{ 1 - cos²θ = sin²θ }
= sin²θ / cos θ
{ sin²θ = sin θ . sin θ }
= sin θ . sin θ / cos θ
{ sin θ / cos θ = tan θ }
= sin θ . tan θ
Hence, simplified.
The solution possible can be correct by dividing both sides by -5 ;Sooo x>-5.....
Answer:
2. B
3. B
4. 2(7k+5h)
5. $325
Step-by-step explanation:
2) "X decreased by the sum of 2x + 5" Decreased means to be lowered, so that means this problem has subtraction in it. It also says x is being decreased BY the sum of 2x + 5 so that means 2x + 5 needs to be solved, which calls for parentheses. B best fits the description.
3) It is B because if you distribute the 8 to 2a and 3b, you'll get 16a and 24b, which is the given expression.
4) The given expression is 10h + 14k and in the equivalent expression, you are given 5h. To get from 10 to 5, you must divide by 2. This tells you that 2 is being distributed, so you put 2 before the parentheses. Since you divided 10 by 2, you want to do the same to 14, which is 7. Therefore, it is 2(7k+5h).
5) You are given the hourly charge, which is $25. This means that they charge $25 per hour/for every hour. You want to find the cost for 13 hours, so you multiply the hourly charge by 13 hours. 25 x 13 = 325.