Answer:
6x+9
Step-by-step explanation:
60x^2+126x+9
6×(10x^2+21x+9)
6×(10x^2+15x+6x+9)
6×5x×(2x+3)+3×(2x+3)
6×(5x+3)(2x+3)
2×(5x+3)×3(2x+3)
(10x+6)(6x+9)
