Question

C= {x:x2 + x - 12= 0 X € N}​

Answer 1

Answer:

x

2

−x−12=0

⟹x

2

−4x+3x−12=0

⟹x(x−4)+3(x−4)=0

⟹(x+3)(x−4)=0

⟹x=−3 or 4

here your answer

Answer 2

C = {x : x² + x - 12 = 0 , X € N}

x² + x - 12 = 0

⇒ x² - 3x + 4x - 12 = 0

⇒ x(x - 3) + 4(x - 3) = 0

⇒ (x+4) (x-3) = 0

Case 1

x + 4 = 0

⇒ x = -4

Case 2

x - 3 = 0

⇒ x = 3

∴ x = { -4 , 3 }