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What-s-the-value-of-a-for-which-x-2-x-a-amp-x-2-3x-2-a-have-one-root-common-




Question Number 161558 by Rasheed.Sindhi last updated on 19/Dec/21
What′s the value of a for which  x^2 +x=a & x^2 −3x+2=a have one  root common?
$${What}'{s}\:{the}\:{value}\:{of}\:{a}\:{for}\:{which} \\ $$$${x}^{\mathrm{2}} +{x}={a}\:\&\:{x}^{\mathrm{2}} −\mathrm{3}{x}+\mathrm{2}={a}\:{have}\:{one} \\ $$$${root}\:{common}? \\ $$
Answered by MJS_new last updated on 19/Dec/21
we′ve got 2 equations for 2 unknowns, just  solve the system  (1) x^2 +x−a=0  (2) x^2 −3x−a+2=0  (1) − (2)  4x−2=0 ⇒ x=(1/2)  ⇒ a=(3/4)
$$\mathrm{we}'\mathrm{ve}\:\mathrm{got}\:\mathrm{2}\:\mathrm{equations}\:\mathrm{for}\:\mathrm{2}\:\mathrm{unknowns},\:\mathrm{just} \\ $$$$\mathrm{solve}\:\mathrm{the}\:\mathrm{system} \\ $$$$\left(\mathrm{1}\right)\:{x}^{\mathrm{2}} +{x}−{a}=\mathrm{0} \\ $$$$\left(\mathrm{2}\right)\:{x}^{\mathrm{2}} −\mathrm{3}{x}−{a}+\mathrm{2}=\mathrm{0} \\ $$$$\left(\mathrm{1}\right)\:−\:\left(\mathrm{2}\right) \\ $$$$\mathrm{4}{x}−\mathrm{2}=\mathrm{0}\:\Rightarrow\:{x}=\frac{\mathrm{1}}{\mathrm{2}} \\ $$$$\Rightarrow\:{a}=\frac{\mathrm{3}}{\mathrm{4}} \\ $$
Commented by Rasheed.Sindhi last updated on 19/Dec/21
∩i⊂∈!   Thanks sir.
$$\cap\mathrm{i}\subset\in!\:\:\:\mathbb{T}\mathrm{han}\Bbbk\mathrm{s}\:\boldsymbol{\mathrm{sir}}. \\ $$

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