Example 5A: Solving Simple Rational Equations Solve. Check your solution. x2 – 25 x – 5 = 14 (x + 5)(x – 5) (x – 5) = 14 Note that x ≠ 5. x + 5 = 14 x = 9
Example 5A Continued x2 – 25 x – 5 = 14 Check (9)2 – 25 9 – 5 14 56 4 14 14 14
Example 5B: Solving Simple Rational Equations Solve. Check your solution. x2 + 3x - 10 x – 2 = 7 (x + 5)(x – 2) (x – 2) = 7 Note that x ≠ 2. x + 5 = 7 x = 2 Because the left side of the original equation is undefined when x = 2, there is no solution.
Example 5B Continued Check A graphing calculator shows that 2 is not a solution.
Check It Out! Example 5a Solve. Check your solution. x2 + x – 12 x + 4 = –7 (x – 3)(x + 4) (x + 4) = –7 Note that x ≠ –4. x – 3 = –7 x = –4 Because the left side of the original equation is undefined when x = –4, there is no solution.
Check It Out! Example 5a Continued Check A graphing calculator shows that –4 is not a solution.
Check It Out! Example 5b Solve. Check your solution. 4x2 – 9 2x + 3 = 5 (2x + 3)(2x – 3) (2x + 3) = 5 Note that x ≠ – . 3 2 2x – 3 = 5 x = 4
Check It Out! Example 5b Continued = 5 Check 4(4)2 – 9 2(4) + 3 5 55 11 5 5 5