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

Building time :
4c + 6a < = 120
testing time :
4c + 4a < = 100
20 child bikes and 6 adult bikes...c = 20 and a = 6
sub into both equations
4c + 6a < = 120
4(20) + 6(6) < = 120
80 + 36 < = 120
116 < = 120 (correct)
4c + 4a < = 100
4(20) + 4(6) < = 100
80 + 24 < = 100
104 < = 100 (incorrect)
ur answer : No, because the bike order does not meet the restrictions of 4c + 6a < = 120 and 4c + 4a < = 100
the list S describes all possible outcomes of the event.
the fourth option
two will get choosen, and the order matters.
Answer:
-4y + 20
Step-by-step explanation:
4(-y+5)
What we need to do here is get rid of the parentheses, which can be achieved through multiplication.
This is another way of saying 4 times -y plus 4 times 5.
Let's break the the parentheses down into 2 separate formulas.
4(-y) and 4(5)
Now we can multiply these two together to get -4y and +20. When combined, we get -4y +20.
Simply you can substitute theta=45 degrees (or any angle,not zero) in left hand side and right hand side.
or
using a^2 - b^2 =(a+b)(a-b)
= sin(2x+x)sin(2x-x)
= sin 3x sin x