$\begin{array}{l}1-\left(-2+7\times 0.15\right)÷2\frac{1}{2}\\ =1-\left(-2+1.05\right)\times \frac{2}{5}\\ =1-\left(-0.95\right)\times \frac{2}{5}\\ =1-\left(-0.38\right)\\ =1.38\end{array}$

$\begin{array}{l}1\frac{1}{8}\times \left(\frac{4}{5}-\frac{2}{3}\right)\\ =1\frac{1}{8}\times \left(\frac{12}{15}-\frac{10}{15}\right)\\ =\frac{{\bcancel{9}}^3}{{\bcancel{8}}_4}\times \frac{{\bcancel{2}}^1}{{\bcancel{15}}_5}\\ =\frac{3}{20}\end{array}$

$\begin{array}{l}-4.6\times \left(\frac{3}{5}-1\frac{3}{4}\right)=-4.6\times \left(0.6-\boxed{1.75}\right)\\ =-4.6\times \boxed{-1.15}\\ =\boxed{5.29}\end{array}$

$\begin{array}{l}-43+35÷1\frac{1}{6}=-43+35÷\frac{7}{6}\\ =-43+35\times \boxed{\frac{6}{7}}\\ =-43+\boxed{30}\\ =-13\end{array}$

$\begin{array}{l}0.6+\left(-1\frac{2}{3}\right)÷\left(\frac{4}{15}\right)-2\\ =0.6+\left[-\frac{5}{\cancel{3}}\times \frac{{\cancel{15}}^5}{4}\right]-2\\ =0.6+\left[-\frac{25}{4}\right]-2\\ =0.6-6\frac{1}{4}-2\\ =0.6-6.25-2\\ =-7.65\end{array}$

$\begin{array}{l}\left(-0.6\times 1\frac{1}{4}\right)-\left[-1.6\times \left(-1.5\right)\right]÷0.4\\ =\left({\cancel{-0.6}}^{-0.3}\times \frac{5}{{\cancel{4}}^2}\right)-\left[\frac{{\cancel{-1.6}}^{-4}\times \left(-1.5\right)}{{\cancel{0.4}}^1}\right]\\ =-\frac{1.5}{2}-6\\ =-0.75-6\\ =-6.75\end{array}$

2. Negative fractions are  fractions with the negative sign (–), and their values are less than 0.

2. Positive decimals are greater than zero and negative decimals are less than zero.