Answer:
[tex]=-3\left(x+1\right)\left(x-3\right)[/tex]
Step-by-step explanation:
[tex]-3x^2+6x+9\\\mathrm{Factor\:out\:common\:term\:}-3:\quad -3\left(x^2-2x-3\right)\\-3x^2+6x+9\\\mathrm{Rewrite\:}9\mathrm{\:as\:}3\cdot \:3\\\mathrm{Rewrite\:}6\mathrm{\:as\:}3\cdot \:2\\=-3x^2+3\cdot \:2x+3\cdot \:3\\\mathrm{Factor\:out\:common\:term\:}-3\\=-3\left(x^2-2x-3\right)\\\mathrm{Factor}\:x^2-2x-3:\quad \left(x+1\right)\left(x-3\right)\\x^2-2x-3\\\mathrm{Break\:the\:expression\:into\:groups}\\=\left(x^2+x\right)+\left(-3x-3\right)[/tex]
[tex]\mathrm{Factor\:out\:}x\mathrm{\:from\:}x^2+x\mathrm{:\quad }x\left(x+1\right)\\x^2+x\\\mathrm{Apply\:exponent\:rule}:\quad \:a^{b+c}=a^ba^c\\x^2=xx\\=xx+x\\\mathrm{Factor\:out\:common\:term\:}x\\=x\left(x+1\right)\\\mathrm{Factor\:out\:}-3\mathrm{\:from\:}-3x-3\mathrm{:\quad }-3\left(x+1\right)\\-3x-3\\\mathrm{Factor\:out\:common\:term\:}-3\\=-3\left(x+1\right)\\=x\left(x+1\right)-3\left(x+1\right)\\\mathrm{Factor\:out\:common\:term\:}x+1\\=\left(x+1\right)\left(x-3\right)[/tex]
[tex]=-3\left(x+1\right)\left(x-3\right)[/tex]
