Answer:
Part 1
The mistake is Step 2: P + 2·x = 2·y
Part 2
The correct answer is
Step 2 correction: P - 2·x = 2·y
(P - 2·x)/2 = y
Step-by-step explanation:
Part 1
The student's steps are;
Step 1; P = 2·x + 2·y
Step 2: P + 2·x = 2·y
Step 3: P + 2·x/2 = y
The mistake in the work is in Step 2
The mistake is moving 2·x to the left hand side of the equation by adding 2·x to <em>P </em>to get; P + 2·x = 2·y
Part 2
To correct method to move 2·x to the left hand side of the equation, leaving only 2·y on the right hand side is to subtract 2·x from both sides of the equation as follows;
Step 2 correction: P - 2·x = 2·x + 2·y - 2·x = 2·x - 2·x + 2·y = 2·y
∴ P - 2·x = 2·y
(P - 2·x)/2 = y
y = (P - 2·x)/2
The answer is (-2, -6)
to rotate 90 degrees counterclockwise, you do (-y, x)
I believe the 3rd answer down if the information you provided is correct
Squaring the sum on the top, rules out 1 and 2 (not squaring the 7 only)
then 4 times the difference. so I believe 4 (x-1) on the bottom.