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36 votes
X^2+10x-39=0
find x

Please Please Please Please Please Please Need Help Now

User Denis Ermolin
by
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2 Answers

7 votes
7 votes

We are given with the equation x² + 10x - 39 = 0 and need to find x, so let's start ;


{:\implies \quad \sf x^(2)+10x-39=0}

By using splitting the middle term method, Rewrite as ;


{:\implies \quad \sf x^(2)+13x-3x-39=0}


{:\implies \quad \sf x(x+13)-3(x+13)=0}


{:\implies \quad \sf (x+13)(x-3)=0}

So, here either (x + 13) = 0 or (x - 3) = 0, when you equate both of them with 0, you will get x = -13 and x = 3

Hence, The required answer is -13 and 3

User Rpayanm
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2.7k points
26 votes
26 votes

Answer :

  • x = 3 or x = -13

Explanation :


\longrightarrow \sf \qquad {x}^(2) + 10x - 39 = 0

We have to find the two numbers a and b such that,


\longrightarrow \sf \qquad a + b = 10


\longrightarrow \sf \qquad a b = 39

Obviously, the two numbers are 3 and 13.


\longrightarrow \sf \qquad {x}^(2) - 3x + 13x - 39 = 0


\longrightarrow \sf \qquad {x}(x - 3)+ 13(x - 3) = 0


\longrightarrow \sf \qquad ({x}+ 13)(x - 3) = 0

Whether, the value of x :


\longrightarrow \sf \qquad {x}+ 13 = 0


\longrightarrow \pmb{\bf \qquad {x} = - 13}

Whether, the value of x :


\longrightarrow \sf \qquad {x} - 3 = 0


{\longrightarrow { \pmb{\bf \qquad {x} = 3}}}

User Joakimk
by
3.1k points