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Question Number 128402 by bramlexs22 last updated on 07/Jan/21 | ||
$$\:\mathrm{If}\:\mathrm{f}\left({x}^{\mathrm{2}} −\mathrm{5}{x}+\mathrm{4}\right)={x}+\mathrm{3}\:\mathrm{then}\:\mathrm{f}\left(−\mathrm{2}\right)=? \\ $$ | ||
Answered by liberty last updated on 07/Jan/21 | ||
$$\Rightarrow\mathrm{x}^{\mathrm{2}} −\mathrm{5x}+\mathrm{4}=−\mathrm{2}\:;\:\mathrm{x}^{\mathrm{2}} −\mathrm{5x}+\mathrm{6}=\mathrm{0} \\ $$$$\:\left(\mathrm{x}−\mathrm{3}\right)\left(\mathrm{x}−\mathrm{2}\right)=\mathrm{0}\:\rightarrow\begin{cases}{\mathrm{x}=\mathrm{3}}\\{\mathrm{x}=\mathrm{2}}\end{cases}\:\Leftrightarrow\mathrm{f}\left(−\mathrm{2}\right)=\begin{cases}{\mathrm{6}}\\{\mathrm{5}}\end{cases} \\ $$ | ||