Find the error and explain why its wrong

The last part.

Step-by-step explanation:

The error is only at the last part. Basically the answer part.

The answer should be —

We don't multiply the square roots when adding or subtracting. That'd contradict the rules.

Here, we let the square root of five as x-term.

As we add up, we would get 13x. Thrn we convert x-term back to square root of five.

The answer would be —

Remember that we don't multiply the square roots when adding or subtracting.

14 ft 7 inches

step-by-step explanation:

since each model inch corresponds to 25 real inches, 7 model inches will correspond to

7×25" = 175"

at 12" per foot, that is 14 feet, 7 inches.