Write the following sets in roster from:

Question:

Write the following sets in roster from:

J = {x : ϵ R and x2 + x – 12 = 0}.

 

Solution:

The given equation is:

$x^{2}+x-12=0$

$\Rightarrow x^{2}+4 x-3 x-12=0$

$\Rightarrow x(x+4)-3(x+4)=0$

$\Rightarrow(x-3)(x+4)=0$

$\Rightarrow x-3=0$ or $x+4=0$

$\Rightarrow x=3$ or $x=-4$

therefore, the solution set of the given equation can be written in roaster form as {3, -4}

So, J = {3, -4}

 

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