Question

tìm x biết 

(1-2x).3 phần 4 mũ 7 = 3 phần 4 mũ 9

Answer 1

(1-2x)* 0.13 = 0.07 (lay xap xi do nha ban )

1-2x = 0.07 /0.13 

1-2x = \(\frac{7}{13}\)

2x = \(\frac{7}{13}\)- 1

2x= \(\frac{-6}{13}\)

x= \(\frac{-6}{13}\) / 2

x= -3 phần 13 

Answer 2

\(\left(1-2x\right)\cdot\left(\frac{3}{4}\right)^7=\left(\frac{3}{4}\right)^9\)

\(\left(1-2x\right)=\left(\frac{3}{4}\right)^9:\left(\frac{3}{4}\right)^7\)

\(1-2x=\left(\frac{3}{4}\right)^2\)

\(1-2x=\frac{9}{16}\)

\(2x=1-\frac{9}{16}\)

\(2x=\frac{7}{16}\)

\(x=\frac{7}{16}:2\)

\(x=\frac{7}{16}\cdot\frac{1}{2}\)

\(x=\frac{7}{32}\)