Answer:
(x+9)×(x-6)
Step-by-step explanation:
1) x²+3x-54
Write 3x as a difference
x²+9x-6x-54
2) x²+9x-6x-54
Factor out x from the expression
x×(x+9)-6x-54
3) x×(x+9)-6x-54
Factor out -6 from the expression
x×(x+9)-6×(x+9)
4) x×(x+9)-6(x+9)
Factor out x + 9 from the expression
(x+9)(x-6)