Al-Khwarizmi shows you immediately how to solve quadratic equations. Read pages 8-10. Use the recipe he presents, plus the translator's footnotes at the bottom, to solve his example problem of "one square, and ten roots of the same, amount to thirty-nine dirhams" (or, x^2 + 10x = 39), and then "two squares and ten roots are equal to forty-eight dirhams" (or, 2x^2 + 10x = 48)