Question

or this problem, the answer choices are "always", "sometimes", or "never".
x • x = 2x
A. Always
B. Sometimes
C. Never

Answer 1

never

Answer 2

as 1not equals 2

Answer 3

B.Sometimes

x * x = 2x
x^2 - 2x = 0
x(x - 2) = 0
x = 0 or x = 2

The equation given in the problem is true if x = 0 or if x = 2.

Answer 4

oh yah @directrix forgot that aspect of the sum

Answer 5

And, dividing by a variable is frequently done but is dicey because if x = 0, you are dividing by 0 which is undefined. In short, you lose one of the two solutions. That's why I factor if I can and avoid dividing through by a variable.

Answer 6

yup, will keep this sum in mind, tricky if you overlook it.