Mistake in Line 2 : Was in the determining the values for a ,b,c
Mistake in Line 4 : Not taking the square roots of both sides.
Step-by-step explanation:

First Mistake : Line 2

Second Mistake : Line 4

Correct Solution :


Answer:
r = 1
Step-by-step explanation:
we know that :

Then

Then

Then
5×12 = 4×(16-r)
Then
60 = 64 - 4r
Then
4r = 64 - 60
Then
4r = 4
Then
r = 1
Answer:
PEMDAS
(5/12) +(23/10)
5/12=0.42
23/10=2.3
0.42+2.3=2.72
2.72 is the correct answer
Answer:
119.
Step-by-step explanation:
12x12 is 144
5x5 is 25
144-25 = 119
All I know is that question 1 is B and I think for question 3 is Sammy is correct.