Answer:
Daniel's Mistake was that she didnt add all the sides
Step-by-step explanation:
She only added the right side of the triangle, and the right and bottom sides of the square. She is missing the left of the triangle, which is another 6x-4, and the left side of the square, which is 12x +3.
Using these sides the answer should look like this,
set up your problem
1) (6x-4)*2 + (12x+3)*2 + (14x+13)
multiply your 2's in
2) (12x-8) + (24x+6) + (14x+13)
simplify
3) 50x + 11 is your answer
