Question and Answers Forum

All Questions      Topic List

Algebra Questions

Previous in All Question      Next in All Question      

Previous in Algebra      Next in Algebra      

Question Number 167374 by mathlove last updated on 14/Mar/22

Answered by nurtani last updated on 14/Mar/22

P=(7+5)(7^2 +5^2 )(7^4 +5^4 ).....(7^(64) +5^(64) )  ⇔ P = (((7−5)(7+5)(7^2 +5^2 )(7^4 +5^4 ).....(7^(64) +5^(64) ))/((7−5)))  ⇔ P = (((7^2 −5^2 )(7^2 +5^2 )(7^4 +5^4 ).....(7^(64) +5^(64) ))/2)  ⇔ P = (((7^4 −5^4 )(7^4 +5^4 ).....(7^(64) +5^(64) ))/2)  ⇒ P = (((7^(64) −5^(64) )(7^(64) +5^(64) ))/2) = ((7^(128) −5^(128) )/2)   ∴ P = (7+5)(7^2 +5^2 )(7^4 +5^4 ).....(7^(64) +5^(64) )= ((7^(128) −5^(128) )/2)

$${P}=\left(\mathrm{7}+\mathrm{5}\right)\left(\mathrm{7}^{\mathrm{2}} +\mathrm{5}^{\mathrm{2}} \right)\left(\mathrm{7}^{\mathrm{4}} +\mathrm{5}^{\mathrm{4}} \right).....\left(\mathrm{7}^{\mathrm{64}} +\mathrm{5}^{\mathrm{64}} \right) \\ $$$$\Leftrightarrow\:{P}\:=\:\frac{\left(\mathrm{7}−\mathrm{5}\right)\left(\mathrm{7}+\mathrm{5}\right)\left(\mathrm{7}^{\mathrm{2}} +\mathrm{5}^{\mathrm{2}} \right)\left(\mathrm{7}^{\mathrm{4}} +\mathrm{5}^{\mathrm{4}} \right).....\left(\mathrm{7}^{\mathrm{64}} +\mathrm{5}^{\mathrm{64}} \right)}{\left(\mathrm{7}−\mathrm{5}\right)} \\ $$$$\Leftrightarrow\:{P}\:=\:\frac{\left(\mathrm{7}^{\mathrm{2}} −\mathrm{5}^{\mathrm{2}} \right)\left(\mathrm{7}^{\mathrm{2}} +\mathrm{5}^{\mathrm{2}} \right)\left(\mathrm{7}^{\mathrm{4}} +\mathrm{5}^{\mathrm{4}} \right).....\left(\mathrm{7}^{\mathrm{64}} +\mathrm{5}^{\mathrm{64}} \right)}{\mathrm{2}} \\ $$$$\Leftrightarrow\:{P}\:=\:\frac{\left(\mathrm{7}^{\mathrm{4}} −\mathrm{5}^{\mathrm{4}} \right)\left(\mathrm{7}^{\mathrm{4}} +\mathrm{5}^{\mathrm{4}} \right).....\left(\mathrm{7}^{\mathrm{64}} +\mathrm{5}^{\mathrm{64}} \right)}{\mathrm{2}} \\ $$$$\Rightarrow\:{P}\:=\:\frac{\left(\mathrm{7}^{\mathrm{64}} −\mathrm{5}^{\mathrm{64}} \right)\left(\mathrm{7}^{\mathrm{64}} +\mathrm{5}^{\mathrm{64}} \right)}{\mathrm{2}}\:=\:\frac{\mathrm{7}^{\mathrm{128}} −\mathrm{5}^{\mathrm{128}} }{\mathrm{2}} \\ $$$$\:\therefore\:{P}\:=\:\left(\mathrm{7}+\mathrm{5}\right)\left(\mathrm{7}^{\mathrm{2}} +\mathrm{5}^{\mathrm{2}} \right)\left(\mathrm{7}^{\mathrm{4}} +\mathrm{5}^{\mathrm{4}} \right).....\left(\mathrm{7}^{\mathrm{64}} +\mathrm{5}^{\mathrm{64}} \right)=\:\frac{\mathrm{7}^{\mathrm{128}} −\mathrm{5}^{\mathrm{128}} }{\mathrm{2}} \\ $$

Commented by TheSupreme last updated on 15/Mar/22

in general  (p+q)Σ_(i=1) ^N (p^(2i) +q^(2i) )=((p^(2N+1) −q^(2N+1) )/(p−q))

$${in}\:{general} \\ $$$$\left({p}+{q}\right)\underset{{i}=\mathrm{1}} {\overset{{N}} {\sum}}\left({p}^{\mathrm{2}{i}} +{q}^{\mathrm{2}{i}} \right)=\frac{{p}^{\mathrm{2}{N}+\mathrm{1}} −{q}^{\mathrm{2}{N}+\mathrm{1}} }{{p}−{q}} \\ $$

Answered by som(math1967) last updated on 14/Mar/22

(7−5)P=(7−5)(7+5)...(7^(64) +5^(64) )   P=((7^(128) −5^(128) )/2)

$$\left(\mathrm{7}−\mathrm{5}\right){P}=\left(\mathrm{7}−\mathrm{5}\right)\left(\mathrm{7}+\mathrm{5}\right)...\left(\mathrm{7}^{\mathrm{64}} +\mathrm{5}^{\mathrm{64}} \right) \\ $$$$\:\boldsymbol{{P}}=\frac{\mathrm{7}^{\mathrm{128}} −\mathrm{5}^{\mathrm{128}} }{\mathrm{2}} \\ $$

Terms of Service

Privacy Policy

Contact: info@tinkutara.com