Algebra
Linear equations →
Learn to solve linear equations and use matching coefficients to recognize an equation with infinitely many solutions.
SAT Math practice and learning guides
Build understanding through original worked examples, clear methods, and questions that use the same concept in a new setting.
Math guides
Algebra
Systems of equations →
Use substitution to solve a system, check both equations, and identify the quantity the question asks for.
Problem-Solving and Data Analysis
Percentages →
Identify the reference quantity, calculate percentage increases or decreases, and check what the result means.