Answer:
3x+ 5 is a factor
Explanation:
Factorization:
9x² + 21x + 10
Sum = 21
Product = 90
Factors = 15 * 6 {15*6=90 & 15+6 = 21}
9x² + 21x + 10 = 9x² + 15x + 6x + 10
{Rewrite the middle term using factors}
= 3x(3x + 5) + 2(3x + 5)
= (3x + 5)(3x + 2)
3x + 5 is a factor.