Answer: C x = -2
Explanation:
![3x^(2) - 30x - 72 = 0](https://img.qammunity.org/2023/formulas/mathematics/high-school/qj8ulwjxp5yufoqhn7ly0upf9w7yvkseiq.png)
[Add 72 on both sides]
![3x^(2) - 30x = 72](https://img.qammunity.org/2023/formulas/mathematics/high-school/aczrn1ar74s20zee8fomgw6k1gsy31sr4b.png)
[Factorise Left Hand Side of equation to get 3 on one side of a bracket]
![3(x^(2) -10x) = 72](https://img.qammunity.org/2023/formulas/mathematics/high-school/vbno2y6k3wrpmdszo0qh3wyg0v3y7ksij8.png)
[Divide each side by 3 to just get the brackets and the x's on one side]
![x^(2) -10x = 24](https://img.qammunity.org/2023/formulas/mathematics/high-school/g05h7tf19h13oabuhvwja938l5uph6bilb.png)
[Minus 24 on both side as the equation must = 0]
![x^(2) -10x-24=0](https://img.qammunity.org/2023/formulas/mathematics/high-school/q01duvuvm46kxubyn4o3rmm7eb3wxk0n59.png)
[Solve the square on the left hand side]
![(x-12)(x+2)=0](https://img.qammunity.org/2023/formulas/mathematics/high-school/qpzxt57ldh42iw0c76pq8i12gvc398idx8.png)
[Solve for x on left hand side - two possible answers]
![x-12=0 \\ x=12](https://img.qammunity.org/2023/formulas/mathematics/high-school/abm8tae3mix1q40l1vm7d7dms1164ue036.png)
![x+2=0\\x=-2](https://img.qammunity.org/2023/formulas/mathematics/college/90xga8r7wqezn0a8okt5k6iuo1cwx49d0i.png)
[The answer '12' is not in the option for the question so '-2' is the answer]