A student was trying to solve the problem below. look at their work and find the error.
identify which line the error is in, describe the error, state what the correct answer should be.
line 1: 2√45 - 3√5
line 2: 2√9 * √5 - 3√5
line 3: 2 * 9 * √5 - 3√5
line 4: 18√5 - 3√5
line 5: 15√5