Question

giải trong N, tìm x biết:

a) 3^x+3^x-1+3^x+1 =39

Answer 1

=> 3^{x - 1} (3 + 1 + 3²) = 39

=> 3^{x - 1}.13 = 39

=> 3^{x - 1} = 39/13

=> 3^{x - 1} = 3

=> x - 1 = 1

=> x = 1 + 1

=> x = 2

Answer 2

tick đi nói cho

 

Answer 3

Đây là toán lớp 6 mà bạn

<=>\(3^x+3^x:3+3^x.3=39\)

<=>\(3^x+3^x.\frac{1}{3}+3^x.3=30\)

<=>\(3^x.\left(1+\frac{1}{3}+3\right)=39\)

<=>\(3^x.\frac{13}{3}=39\)

<=>\(3^x=3\)

<=>\(x=1\)

 Nếu thấy bài làm của mình đúng thì tick nha bạn,cảm ơn.

Answer 4

TL

x=2

Hok tốt

Answer 5

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