Tính giá trị biểu thức -5/12 + 1 + 5/18 - 2,25

\( - \frac{5}{{12}} + 1 + \frac{5}{{18}} - 2,25\)

\( = \frac{5}{{18}} - \frac{5}{{12}} - 1,25\)

\( = \frac{5}{{18}} - \frac{5}{{12}} - \frac{5}{4}\)

\( = \frac{5}{{18}} - \frac{5}{{12}} - \frac{5}{4}\)

\( = \frac{{5.2}}{{18.2}} - \frac{{5.3}}{{12.3}} - \frac{{5.9}}{{4.9}}\)

\( = \frac{{10}}{{36}} - \frac{{15}}{{36}} - \frac{{45}}{{36}}\)

\( = \frac{{10 - 15 - 45}}{{36}} = \frac{{ - 50}}{{36}} = \frac{{ - 25}}{{18}}\).