Advanced Math practice question

Answer: 6 or -2 or 6.0 or -2.0

A product equals 0 only when one factor equals 0. Setting x − 6 = 0 gives x = 6, and setting x + 2 = 0 gives x = −2; either value is acceptable. Common errors this item targets: reversing the signs of the factors (answering −6 or 2), which comes from reading the constant inside each factor as the zero itself rather than solving x − 6 = 0 and x + 2 = 0; and multiplying the constants to get −12, which is the y-intercept h(0), not a zero.

Common wrong answers

If you answered 2

You read the constant in (x + 2) as the zero; solving x + 2 = 0 gives x = −2, not 2.

If you answered -6

You read the constant in (x − 6) as the zero itself; solving x − 6 = 0 actually gives x = 6.

If you answered -12

That's h(0), the product of the two constants — the y-intercept, not a value of x that makes h(x) = 0.

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