Final answer:
Cross multiplication is used to solve rational equations that take the form of proportions, i.e., when a ratio (fraction) equals to another ratio. The process involves multiplying the diagonals, resulting in a simpler, non-fraction equation.
Step-by-step explanation:
In the context of solving a rational equation, the condition under which you should make use of cross products is when you have a proportion. In other words, when you have an equation that is a fraction set equal to another fraction - a/b = c/d, then you can use cross multiplication to solve this rational equation. Here's the step by step:
- Firstly, apply the cross multiplication rule where you multiply the diagonals, giving you a*d = b*c.
- This results in an equation which is no longer a fraction and can be more easily solved.
Cross multiplication simplifies the process of finding the solution to a rational equation and is a tool you should use when equations take the form of a proportion.
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