How to arrange the equation after Leftrightarrow sign?
\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{amsfonts}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{float}
\usepackage{graphics}
\begin{document}
\begin{equation}
\begin{aligned}
& \Leftrightarrow - \scalebox{0.975}{$\biggl(\left(\alpha + \mu + \rho\right)\left(\left( a_1 + \left( \alpha + \mu\right)\right)^2 + a_1 a_2\right) + \left( a_1 + \left(\alpha + \mu\right)\right)\gamma \rho \biggr)$} > 0 \
& \Leftrightarrow \left(\alpha + \mu + \rho\right)\left(\left( a_1 + \left( \alpha + \mu\right)\right)^2 + a_1 a_2\right) + \left( a_1 + \left(\alpha + \mu\right)\right)\gamma \rho < 0 \
& \Leftrightarrow \scalebox{0.875}{$\left(\alpha + \mu + \rho\right)\left(\left(\frac{\Lambda\beta \left(\alpha+\mu+\rho\right)}{\left(\alpha+ \mu\right)\left(\alpha + \mu + \gamma + \rho\right)}\right)^2 + \Lambda \beta - \frac{\left(\alpha+ \mu\right)^2\left(\alpha + \mu + \gamma + \rho\right)}{\alpha+\mu+\rho}\right) + \left(\frac{\Lambda\beta \left(\alpha+\mu+\rho\right)}{\left(\alpha+ \mu\right)\left(\alpha + \mu + \gamma + \rho\right)}\right)\gamma \rho$} < 0 \
& \Leftrightarrow \scalebox{0.85}{$\left(\alpha + \mu + \rho\right)\left(\frac{\Lambda\beta \left(\alpha+\mu+\rho\right)}{\left(\alpha+ \mu\right)\left(\alpha + \mu + \gamma + \rho\right)}\right)^2+ \Lambda \beta\left(\alpha + \mu + \rho\right) - \left(\alpha+ \mu\right)^2\left(\alpha + \mu + \gamma + \rho\right) $} \
& \scalebox{0.9}{$ + \left(\frac{\Lambda\beta \left(\alpha+\mu+\rho\right)}{\left(\alpha+ \mu\right)\left(\alpha + \mu + \gamma + \rho\right)}\right)\gamma \rho $} < 0 \
& \Leftrightarrow \scalebox{0.9}{$\left(\alpha+ \mu\right)^2\left(\alpha + \mu + \gamma + \rho\right)$} > \
& \scalebox{0.9}{$\left(\alpha + \mu + \rho\right)\left(\frac{\Lambda\beta \left(\alpha+\mu+\rho\right)}{\left(\alpha+ \mu\right)\left(\alpha + \mu + \gamma + \rho\right)}\right)^2+ \Lambda \beta\left(\alpha + \mu + \rho\right) + \left(\frac{\Lambda\beta \left(\alpha+\mu+\rho\right)}{\left(\alpha+ \mu\right)\left(\alpha + \mu + \gamma + \rho\right)}\right)\gamma \rho$} \
\end{aligned}
\end{equation}
\end{document}



\Leftrightarrow, move the&after the\Leftrightarrow. Leave it where it is in the other lines. But there are other (better) ways to get smaller type than using\scalebox; I believe there's another question dealing with that, but it may take a while to find it. – barbara beeton Jan 09 '22 at 03:32\smallto resize a math display affects the baseline stretch of the preceding paragraph – barbara beeton Jan 09 '22 at 03:43\leftand\rightfor every single parenthesis? I can count more than 50 [!] instances each of\leftand\right... – Mico Jan 09 '22 at 06:04