A rational equation has the variable in a denominator. Rule out inputs that make a denominator zero, then graph the original two sides in Desmos to find the real solutions. If clearing the fractions leaves a quadratic, its coefficients give you an exact product. Don’t multiply rounded graph coordinates or count an input the original equation forbids.
Hints
- Hint 1
A denominator of makes a fraction undefined. Find the values that make either denominator zero before you clear the fractions, so you can check which solutions are allowed.
- Hint 2
Graph each side of the original equation separately. An intersection is where the two sides have the same value; its -coordinate is a real solution. How many intersections can you find?
- Hint 3
Multiplying every term by clears both fractions. If the result is a quadratic, you can get the exact product of its roots from its coefficients without finding each root.
Step-by-step
Graph the solutions, then find their exact product
Step 1Rule out undefined inputs
The restrictions are values that make the original equation undefined. Since division by is undefined, rules out , and rules out . Keep both restrictions after the fractions disappear.
- Step 2
Find the real solutions on the graph
Type and . Click both intersections. Desmos shows and . Each makes the original sides equal, and neither is a restricted value. Use the graph to count the solutions, not their rounded coordinates to calculate an exact product.
- Step 3
Clear both denominators
Multiply every term by , the least common denominator. Each fraction’s denominator cancels with its matching factor; the on the right gets multiplied too:
- Step 4
Expand the products
Distribute each factor, keeping the minus sign in :
- Step 5
Combine like terms
Combine like terms, which have the same power of :
- Step 6
Put the quadratic in standard form
Subtract from both sides so the quadratic has on one side:
- Step 7
Use the root product
For , the product of its roots is . The graph showed that both roots are real and allowed. Here and , so:
The product of all real solutions is . Grid in -1.