SAT Math Practice Exam

Answer A - Use simple algebraic formula . First take out common multiple 3

3 (x² -9)/ (x+3) = 3 (x² -3²)/ (x+3) = 3 (x+3) (x-3)/ (x+3) = 3(x-3) = 3x-9

Key takeaway: To simplify an expression, think of hidden multiples, factors and application of of simple algebraic formulae. Always search possibility of crossing same factors in the numerator and the denominator.