Mathematics for IGCSE & O level - Algebraic Manipulation (Section 6 - No. 13)
When factorizing x² + bx + c and 'c' is positive, what is the rule for the signs of the factors?
The factors must have different signs.
Both factors must be positive.
Both factors must be negative.
Both factors have the same sign as the coefficient of 'b'.
Explication
If 'c' is positive, the factors have the same sign, which is determined by the sign of 'b'.