a/\(\frac{13}{11}.\frac{22}{26}-x^2=\frac{7}{16}\)
\(\Rightarrow1-x^2=\frac{7}{16}\)
\(\Rightarrow x^2=\frac{9}{16}\)
\(\Rightarrow x=\orbr{\begin{cases}\frac{3}{4}\\-\frac{3}{4}\end{cases}}\)
\(a,\frac{13}{11}.\frac{22}{26}-x^2=\frac{7}{16}\)
\(1-x^2=\frac{7}{16}\)
\(x^2=1-\frac{7}{16}=\frac{9}{16}\)
\(\Rightarrow\orbr{\begin{cases}x=\frac{3}{4}\\x=-\frac{3}{4}\end{cases}}\)
\(b,x^2+-\frac{9}{25}=\frac{2}{5}.\frac{8}{5}\)
\(x^2+-\frac{9}{25}=\frac{16}{25}\)
\(x^2=\frac{16}{25}--\frac{9}{25}=1\)
\(\Rightarrow\orbr{\begin{cases}x=1\\x=-1\end{cases}}\)
học tốt ~~~
a/ \(\frac{13}{11}.\frac{22}{26}-x^2=\frac{7}{16}\)
\(\Rightarrow\)\(1-x^2=\frac{7}{16}\)
\(\Rightarrow\)\(x^2=1-\frac{7}{16}\)
\(\Rightarrow\)\(x^2=\frac{9}{16}\)
\(\Rightarrow\)\(x^2=\left(\frac{3}{4}\right)^2\)
\(\Rightarrow\)\(x=\frac{3}{4}\)
b, \(x^2+\frac{-9}{25}=\frac{2}{5}.\frac{8}{5}\)
\(\Rightarrow x^2+\frac{-9}{25}=\frac{16}{25}\)
\(\Rightarrow x^2=\frac{16}{25}-\frac{-9}{25}\)
\(\Rightarrow x^2=\frac{25}{25}\)
\(\Rightarrow x^2=\left(\frac{5}{5}\right)^2=\left(\frac{-5}{5}\right)^2\)
\(\Rightarrow x=\frac{5}{5}=\frac{-5}{5}\)
\(\Rightarrow x=1=-1\)
\(\Rightarrow x=\pm1\)
