Question

tìm x thuộc n

a)3.5ⁿ⁺²+4.5^n-3=19.5¹⁰

b)11.6^x-1+2.6^x+1=11.6¹¹+2.6¹³

help me :(( mjk tick cho

Answer 1

a: \(\Leftrightarrow3\cdot5^n\cdot25+4\cdot5^n\cdot\dfrac{1}{125}=19\cdot5^{10}\)

\(\Leftrightarrow5^n\cdot\left(75+\dfrac{4}{125}\right)=19\cdot5^{10}\)

\(\Leftrightarrow5^n\simeq2472903,228\)(vô lý)

b: \(\Leftrightarrow6^x\cdot11\cdot\dfrac{1}{6}+2\cdot6^x\cdot6=11\cdot6^{11}+2\cdot6^{11}\cdot36\)

\(\Leftrightarrow6^x\left(\dfrac{11}{6}+12\right)=6^{11}\cdot83\)

\(\Leftrightarrow6^x=6^{12}\)

hay x=12