HII HELP PLEASE! I DONT UNDERSTAND

Question

asked May 24, 2023 83.4k views

2 Answers

Raj Verma · Answer 1 · 2023-05-25T13:41:27+0000

Answer: C x = -2

Explanation:

3x^(2) - 30x - 72 = 0

[Add 72 on both sides]

3x^(2) - 30x = 72

[Factorise Left Hand Side of equation to get 3 on one side of a bracket]

3(x^(2) -10x) = 72

[Divide each side by 3 to just get the brackets and the x's on one side]

x^(2) -10x = 24

[Minus 24 on both side as the equation must = 0]

x^(2) -10x-24=0

[Solve the square on the left hand side]

(x-12)(x+2)=0

[Solve for x on left hand side - two possible answers]

$x-12=0 \\ x=12$

$x+2=0\\x=-2$

[The answer '12' is not in the option for the question so '-2' is the answer]