Incomplete quadratics
For ax² + c = 0, make x² the subject and take the square root (two opposite solutions or none); solve ax² + bx = 0 by taking out x, never by dividing by x.
Quadratic equations are the big step up in algebra in Grade 9: from incomplete quadratics, solved by making x² the subject or taking out x, to the quadratic formula and the discriminant. This free quadratic equations worksheet generator builds A4 worksheets of equations made from their solutions, with an answer key that shows every step.
Student worksheet
Answer key For ax² + c = 0, make x² the subject and take the square root (two opposite solutions or none); solve ax² + bx = 0 by taking out x, never by dividing by x.
Identify a, b and c, work out b² − 4ac with brackets around negative numbers and use x = (−b ± √(b² − 4ac))/2a to reach both solutions in their simplest form.
Products, squared brackets such as (x + 3)², x on both sides and fractions: everything is brought to ax² + bx + c = 0 before solving.
Two solutions, one repeated root or none depending on the sign of b² − 4ac, without solving. In Grade 10, the value of k that gives a repeated root.
From the roots to the equation with x² − Sx + P = 0, including fraction roots, and the classic puzzle of two numbers with a given sum and product.
Every step named with its result: clear the fractions, expand, collect terms, simplify, the discriminant, the formula and the solutions highlighted.