If-one-zero-of-the-quadratic-polynomial-x-2-7x-k-is-2-then-find-the-value-of-k-

Question Number 9792 by Basant007 last updated on 04/Jan/17

Answered by RasheedSoomro last updated on 05/Jan/17

If one zero of the quadratic polynomial x^2 +7x +k is 2 then find the value of k −−−− −−−− −−−−− 2 is one 0 of x^2 +7x+k means 2 is one solution of x^2 +7x+k=0 (2)^2 +7(2)+k=0 k=−18

$$\mathrm{If}\:\mathrm{one}\:\mathrm{zero}\:\mathrm{of}\:\mathrm{the}\:\mathrm{quadratic}\:\mathrm{polynomial} \\ $$$$\mathrm{x}^{\mathrm{2}} +\mathrm{7x}\:+\mathrm{k}\:\mathrm{is}\:\mathrm{2}\:\mathrm{then}\:\mathrm{find}\:\mathrm{the}\:\mathrm{value}\:\mathrm{of}\:\:\mathrm{k} \\ $$$$−−−−\:\:\:\:\:\:\:\:\:\:−−−−\:\:\:\:\:\:\:\:\:\:\:−−−−− \\ $$$$\mathrm{2}\:\:\mathrm{is}\:\mathrm{one}\:\:\mathrm{0}\:\mathrm{of}\:\mathrm{x}^{\mathrm{2}} +\mathrm{7x}+\mathrm{k}\:\mathrm{means}\:\mathrm{2}\:\mathrm{is}\:\mathrm{one} \\ $$$$\mathrm{solution}\:\mathrm{of}\:\mathrm{x}^{\mathrm{2}} +\mathrm{7x}+\mathrm{k}=\mathrm{0} \\ $$$$\:\:\:\:\:\:\:\left(\mathrm{2}\right)^{\mathrm{2}} +\mathrm{7}\left(\mathrm{2}\right)+\mathrm{k}=\mathrm{0} \\ $$$$\:\:\:\:\:\:\:\:\:\:\mathrm{k}=−\mathrm{18} \\ $$$$ \\ $$

Commented by Basant007 last updated on 04/Jan/17