**TO FACTOR WHEN CONSTANT TERM POSITIVE OR NEGATIVE**

**TO FACTOR **x^{2} + bx + c **WHEN IS POSITIVE**

When the constant term of a trinomial is positive, look for two numbers with the same sign. The sign is that of the middle term:

x^{2} – 7x + 10 = (x – 2) (x – 5);

x^{2} + 7x + 10 = (x + 2) (x + 5).

**TO FACTOR ** x^{2} + bx + c** WHEN IS NEGATIVE**

When the constant term of a trinomial is negative, look for two numbers whose product is negative. One must be positive and the other negative:

x^{2 }– 4x – 21 = (x + 3) (x – 7);

x^{2 }+ 4x – 21 = (x – 3) (x + 7).

Consider pairs of numbers for which the number with the larger absolute value has the same sign as *b*, the coefficient of the middle term.

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