9.6 Solving Rational Equations p.569
Short Cut! When there is only fraction on each side of the equal sign, just cross-multiply as if you are solving a proportion.
Example: Solve. Check your solutions!
Example: Solve. Check your solutions!
Hint for solving: One method to solve a rational equation is to multiply everything through by the LCD. This will get rid of all the fractions! Beware of extraneous solutions!
Multiply each fraction through by the LCD Example: Solve. LCD: 2x Multiply each fraction through by the LCD Check your solution!
Solve. LCD: ? LCD: (x+1) ? Check your solution! No Solution!
Solve. Factor 1st! LCD: (x+2)(x-2) Check your solutions!
Here is another example that we will do together:
Step 1: Find the LCD This denominator can be factored into 3(x-2) Hint: Factor the denominator This denominator can be factored into 3(x-2) But you need at least a 6 from the other denominator Therefore….
Step 2: Multiply both sides of equation by LCD Step 2: Multiply both sides of equation by LCD. This eliminates the fractions when you cancel the matching factors.
Step 3: Solve for x
Since there are two answers, there need to be two checks. Let x =
Check #2: Let x = 2 When you check the number 2, you get a zero in the denominator. This means that 2 can not be a solution.
Now, you do these on your own.