Common Maths Mistakes (Part 1 of 4)

Detect and correct your algebraic errors and become mathematically independent by understanding expressions rather than memorising lots of rules. This screencast focuses on common mistakes and misconceptions and shows you how to avoid them as well as techniques for checking your algebraic steps.

[DanDart]

I'd solve that second one differently to make sure I didn't miss anything. Since it was a quadratic to start with I'd multiply out and leave the factoring to the end once I had 0 on one side:

x(2-x) = x²
2x - x² = x²
2x² - 2x = 0
x² - x = 0
x(x - 1) = 0
x = 1 or 0

[herozeropinto]

in the division by 0 example. a-b=0 as a=b henve 0=0