Question

Tìm x biết :

\(172x^2-7^9:98^3=2^{-3}\)

Answer 1

172x² - 7⁹:93³ = 2^-3

172x² - 42,875 = 0,125

172x² = 0,125 + 42,875

172x² = 43

x² = 172 : 43

x² = 4

x = \(\sqrt{4}\) = 2 ( 2² = 4 )

Vậy x = 2

Answer 2

172x^2 - 7^9 : 98^3 = 2^-3

172x^2 - 7^9 : 98^3 = 1/8

172x^2 - 7^9 : ( 7^3 ) ^ 3 = 1/8

172x^2 - 7^ 9 : 7^9 = 1/8

172x^2 - 1 = 1/8

Answer 3

Nguyen ngoc dat yêu cầu là tính x chứ không phải tính 172x²-1 nhé

Answer 4

ta có : 172x² - (7³)³ : 98³ = 2^-3 \(\Leftrightarrow172x^2-343^3:98^3=2^{-3}\)\(\Leftrightarrow172x^2-\left(\frac{7}{2}\right)^3=2^{-3}\)

\(\Leftrightarrow172x^2=2^{-3}+\left(\frac{7}{2}\right)^3\)\(\Leftrightarrow172x^2=43\)\(\Leftrightarrow x^2=43:172\)\(\Leftrightarrow x^2=\frac{1}{4}\)\(\Leftrightarrow x=\sqrt{\frac{1}{4}}\)

\(\Leftrightarrow x=\frac{1}{2}\)