Question

Tìm x biết:

5^x+5^x+2=6503^x-1+5*3^x-1=162

Answer 1

     5^X+5^X+2=650

=>5^X.1+5^X.5²=650

=>5^X.(1+5²)=650

=>5^X.26=650

=>5^x=650:26

=>5^X=25

=>5^X=5²

=>X=2

 

     3^X-1+5.3^X-1=162

=>3^X-1.1+5.3^X-1=162

=>3^X-1.(1+5)=162

=>3^X-1.6=162

=>3^X-1=162:6

=>3^X-1=27

=>3^X-1=3³

=>3^X=3³⁺¹

=>3^X=3⁴

=>X=4

Answer 2

\(5^x+5^{x+2}=650\Leftrightarrow5^x+5^x.5^2=650\)

\(5^x=650:26=25\Leftrightarrow x=2\)

Answer 3

5^x+5^x+2=650

<=>5^x.(1+5²)=650

<=>5^x.26=650

<=>5^x=650:26

<=>5^x=25=5²

<=>x=2

3^x-1+5.3^x-1=162

<=>3^x-1(1+5)=162

<=>3^x-1.6=162

<=>3^x-1=162:6

<=>3^x-1=27=3³

<=>x-1=3

<=>x=4

Answer 4

x+2x+3x+4x+5x+....+2011x=2012.2013

Answer 5

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