Question

In solving the equation (x + 1)(x – 2) = 4, Eric stated that the solution would be
x + 1 = 4 => x = 3
or
(x – 2) = 4 => x = 6
However, at least one of these solutions fails to work when substituted back into the original equation. Why is that? Please help Eric to understand better; solve the problem yourself, and explain your reasoning. (Points : 20)

Answer 1

Online College?

Answer 2

yep

Answer 3

discussion question/

Answer 4

Univ of Phenoix?

Answer 5

no

Answer 6

Eric doesn't know what he's talking about.

Answer 7

Eric is such a Failure.

Answer 8

you have to write an essay right?

Answer 9

of about 50 words?

Answer 10

nope

Answer 11

then/

Answer 12

\[(x + 1)(x – 2) = 4\]\[x^2-x-6=0\]
\[x=-2\] or\[x=3\]