21Factoring x²−5x−24
Factor , then solve .
The expression factors as (x+3)(x−8), since 3 and −8 multiply to −24 and add to −5. Setting each factor to zero gives x = −3 or x = 8. Check: 8² − 5(8) − 24 = 64 − 40 − 24 = 0.
Factor , then solve .
The expression factors as (x+3)(x−8), since 3 and −8 multiply to −24 and add to −5. Setting each factor to zero gives x = −3 or x = 8. Check: 8² − 5(8) − 24 = 64 − 40 − 24 = 0.