Factoring quadratics

Find two numbers that multiply to c and add to b — the quadratic factor trick.

To factor x² + bx + c, find two numbers that multiply to c and add to b.

Try it

x² + 7x + 12

Need two numbers: ×12, +7. That's 3 and 4. So (x+3)(x+4).

Try it

x² − 5x + 6

Need ×6, −5. That's −2 and −3. So (x−2)(x−3).