\(x = {-b \pm \sqrt{b^2-4ac} \over 2a}\)
\(d,\left(1-\frac{3}{4}\right)\left(1+\frac{1}{3}\right):\left(1-\frac{1}{3}\right)\)
\(=\frac{1}{4}.\frac{4}{3}.\frac{3}{2}\)
\(=\frac{1}{2}\)
\(=\left(1-\frac{3}{4}\right)x\left(1+\frac{1}{3}\right):\left(1-\frac{1}{3}\right)\)
\(=\frac{1}{4}x\frac{4}{3}:\frac{2}{3}\)
\(=\frac{4}{12}:\frac{2}{3}\)
\(=\frac{12}{24}\)
rút gọn là\(\frac{1}{2}\)