Hàm số mũ khó

M

maxqn

$$\begin{aligned} pt \Leftrightarrow & \frac{(x^2+3x+2)3^x}{3} = 2^x(x+2) \\ \Leftrightarrow & \left[ \begin{array}{} x = -2 \\ \left( \frac32 \right)^x = \frac3{x+1} \ \ (x \not= -1) \end{array} \right. \\ \Leftrightarrow & \left[ \begin{array}{} x = -2 \\ x = 1 \end{array} \right. \end{aligned}$$

Vậy $x = -2 \vee x = 1$
 
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T

tranvanduc93

Dk:x thuoc R
Ban bien doj p trjh ve dag 3^x(x+2)(x+1)=3.(x+2).2^x
TH1:x=-2
TH2: (x+1).3^x=3.2^x
suy ra x+1=3.(2/3)^x
nhan xet: VT la ham dog bjen con VP la ham nghjch bjen .dung pp ham so de chj ra neu pt co ngjem thj ngjem do la duy nhat
thax x=1 la ngjem dux nhat
vax pt co ngjem x=-2 va x=1
 
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