\documentclass[12pt,a4paper,french]{article}
\usepackage[utf8]{inputenc}
\usepackage{amsmath}
\usepackage{lmodern}
\usepackage{babel}
\begin{document}
\begin{align*}
(-7x + 2)(2x + 5) & = -14x^2 - 31x + 10\\
(-7x - 6)(4x + 9) & = -28x^2 - 87x - 54\\
(-5x - 9)(8x - 3) & = -40x^2 - 57x + 27\\
(-7x + 6)(-3x - 2) & = 21x^2 - 4x - 12\\
(-5x - 3)(2x - 5) & = -10x^2 + 19x + 15\\
(4x - 7)(6x - 9) & = 24x^2 - 78x + 63\\
(-8x + 2)(-5x + 3) & = 40x^2 - 34x + 6\\
(6x - 6)(7x + 9) & = 42x^2 + 12x - 54\\
(3x + 5)(7x + 4) & = 21x^2 + 47x + 20\\
(-7x - 7)(-4x - 7) & = 28x^2 + 77x + 49\\
(-6x + 3)(-3x + 3) & = 18x^2 - 27x + 9\\
(-2x - 6)(6x + 3) & = -12x^2 - 42x - 18\\
(-7x + 7)(-3x - 7) & = 21x^2 + 28x - 49\\
(-7x - 2)(6x - 9) & = -42x^2 + 51x + 18\\
(-3x + 6)(2x - 7) & = -6x^2 + 33x - 42\\
(3x - 9)(6x - 8) & = 18x^2 - 78x + 72\\
(-3x - 8)(4x + 2) & = -12x^2 - 38x - 16\\
(-6x - 7)(8x + 7) & = -48x^2 - 98x - 49\\
(6x + 5)(6x + 7) & = 36x^2 + 72x + 35\\
(-7x - 4)(4x + 5) & = -28x^2 - 51x - 20\\
(-2x - 3)(5x - 5) & = -10x^2 - 5x + 15\\
\end{align*}
\end{document}