Question

Find the error and explain why its wrong

Answer 1

Answer:

The last part.

Step-by-step explanation:

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

The answer should be —

$13 \sqrt{5}$

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.

$\sqrt{5} = x$

$4 \sqrt{5} + 9 \sqrt{5} = 4x + 9x$

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

The answer would be —

$13x \\ x = \sqrt{5} \\ 13 \sqrt{5}$

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