Advanced Math practice question

Answer: -4 or −4

Set the expressions equal: x² − 3x = 4, so x² − 3x − 4 = 0, which factors as (x − 4)(x + 1) = 0. The x-coordinates are 4 and −1, and their product is −4.

Common wrong answers

If you answered 3

3 is the SUM of the x-coordinates (4 + (−1)). The question asks for the product.

If you answered 4

4 is one of the x-coordinates (and also the y-value of the line). The other x-coordinate is −1, and 4 × (−1) = −4.

If you answered -3

−3 has the wrong sign for the sum and isn't the product either. Factor x² − 3x − 4 as (x − 4)(x + 1).

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