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# plz help

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If  (2x+5)(x-3)=14+7x-8, find the sum of the possible values of x.

Apr 17, 2022

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Expand and move every term to one side.

$$\begin{array}{rcl} (2x + 5)(x - 3) &=& 14 + 7x -8\\ 2x^2 + 5x - 6x - 15 &=& 14 + 7x - 8\\ 2x^2 -8x-7&=&0 \end{array}$$

Let a and b be the possible values of x. Then by Vieta's formulae, $$a + b = 4$$.

Therefore, the sum of possible values of x is 4.

Apr 17, 2022