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 92448 by jagoll last updated on 07/May/20

 { ((5^x .6^y  = 150)),((5^y .6^x  = 180 )) :}

$$\begin{cases}{\mathrm{5}^{\mathrm{x}} .\mathrm{6}^{\mathrm{y}} \:=\:\mathrm{150}}\\{\mathrm{5}^{\mathrm{y}} .\mathrm{6}^{\mathrm{x}} \:=\:\mathrm{180}\:}\end{cases} \\ $$

Commented by john santu last updated on 07/May/20

����������

Answered by john santu last updated on 07/May/20

Commented by jagoll last updated on 07/May/20

☺☺��

Answered by $@ty@m123 last updated on 07/May/20

5^x .6^x .5^y .6^x =150×180  5^(x+y) .6^(x+y) =27000  30^(x+y) =30^3   x+y=3

$$\mathrm{5}^{{x}} .\mathrm{6}^{{x}} .\mathrm{5}^{{y}} .\mathrm{6}^{{x}} =\mathrm{150}×\mathrm{180} \\ $$$$\mathrm{5}^{{x}+{y}} .\mathrm{6}^{{x}+{y}} =\mathrm{27000} \\ $$$$\mathrm{30}^{{x}+{y}} =\mathrm{30}^{\mathrm{3}} \\ $$$${x}+{y}=\mathrm{3} \\ $$

Commented by jagoll last updated on 07/May/20

��

Answered by Rasheed.Sindhi last updated on 07/May/20

    6(5^x .6^y )=6(150)                    ⇒5^x .6^(y+1) =900......(i)        5(5^y .6^x ) = 5(180)                     ⇒5^(y+1) .6^x =900.....(ii)  (i)/(ii):  (5^x .6^(y+1) )/(5^(y+1) .6^x )=1                        5^(x−y−1) .6^(y−x+1) =5^0 .6^0   ⇒x−y=1  ...............................(i)        x+y=3  (By S@ty@m sir)....(ii)               From (i) & (ii)  x=2,y=1

$$\:\:\:\:\mathrm{6}\left(\mathrm{5}^{{x}} .\mathrm{6}^{{y}} \right)=\mathrm{6}\left(\mathrm{150}\right) \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\Rightarrow\mathrm{5}^{{x}} .\mathrm{6}^{{y}+\mathrm{1}} =\mathrm{900}......\left({i}\right) \\ $$$$\:\:\:\:\:\:\mathrm{5}\left(\mathrm{5}^{\mathrm{y}} .\mathrm{6}^{\mathrm{x}} \right)\:=\:\mathrm{5}\left(\mathrm{180}\right) \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\Rightarrow\mathrm{5}^{{y}+\mathrm{1}} .\mathrm{6}^{{x}} =\mathrm{900}.....\left({ii}\right) \\ $$$$\left({i}\right)/\left({ii}\right):\:\:\left(\mathrm{5}^{{x}} .\mathrm{6}^{{y}+\mathrm{1}} \right)/\left(\mathrm{5}^{{y}+\mathrm{1}} .\mathrm{6}^{{x}} \right)=\mathrm{1} \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\mathrm{5}^{{x}−{y}−\mathrm{1}} .\mathrm{6}^{{y}−{x}+\mathrm{1}} =\mathrm{5}^{\mathrm{0}} .\mathrm{6}^{\mathrm{0}} \\ $$$$\Rightarrow{x}−{y}=\mathrm{1}\:\:...............................\left({i}\right) \\ $$$$\:\:\:\:\:\:{x}+{y}=\mathrm{3}\:\:\left({By}\:{S}@{ty}@{m}\:{sir}\right)....\left({ii}\right)\:\:\:\:\:\:\:\:\:\:\:\:\: \\ $$$${From}\:\left({i}\right)\:\&\:\left({ii}\right) \\ $$$${x}=\mathrm{2},{y}=\mathrm{1} \\ $$$$ \\ $$

Answered by Rasheed.Sindhi last updated on 07/May/20

By Factorization  150 and 180 can be written as   product of 5 & 6:    { ((5^x .6^y =150=2.3.5^2 =5^2 .6^1 )),((5^y .6^x =180=2^2 .3^2 .5=5^1 .6^2 )) :}  ⇒x=2 ∧ y=1

$${By}\:{Factorization} \\ $$$$\mathrm{150}\:{and}\:\mathrm{180}\:{can}\:{be}\:{written}\:{as}\: \\ $$$${product}\:{of}\:\mathrm{5}\:\&\:\mathrm{6}: \\ $$$$\:\begin{cases}{\mathrm{5}^{{x}} .\mathrm{6}^{{y}} =\mathrm{150}=\mathrm{2}.\mathrm{3}.\mathrm{5}^{\mathrm{2}} =\mathrm{5}^{\mathrm{2}} .\mathrm{6}^{\mathrm{1}} }\\{\mathrm{5}^{{y}} .\mathrm{6}^{{x}} =\mathrm{180}=\mathrm{2}^{\mathrm{2}} .\mathrm{3}^{\mathrm{2}} .\mathrm{5}=\mathrm{5}^{\mathrm{1}} .\mathrm{6}^{\mathrm{2}} }\end{cases} \\ $$$$\Rightarrow{x}=\mathrm{2}\:\wedge\:{y}=\mathrm{1} \\ $$

Commented by Prithwish Sen 1 last updated on 08/May/20

wow!

$$\mathrm{wow}! \\ $$

Commented by Rasheed.Sindhi last updated on 08/May/20

ThαnX sir.  Moreover:  If in an equation a^x .b^y =c,  c can be  written as a product of a & b in  a unique way (as in this case) only  one equation is sufficient!

$$\mathcal{T}{h}\alpha{n}\mathcal{X}\:{sir}. \\ $$$${Moreover}: \\ $$$${If}\:{in}\:{an}\:{equation}\:{a}^{{x}} .{b}^{{y}} ={c},\:\:{c}\:{can}\:{be} \\ $$$${written}\:{as}\:{a}\:{product}\:{of}\:{a}\:\&\:{b}\:{in} \\ $$$${a}\:\boldsymbol{{unique}}\:{way}\:\left({as}\:{in}\:{this}\:{case}\right)\:{only} \\ $$$${one}\:{equation}\:{is}\:{sufficient}! \\ $$

Commented by Prithwish Sen 1 last updated on 08/May/20

agree

$$\mathrm{agree} \\ $$

Terms of Service

Privacy Policy

Contact: info@tinkutara.com