Rational equation
Master rational equation in Grade 9 math — If it's a proportion, you can solve it using cross products: if $\frac{a}{b} = \frac{c}{d}$, then $ad = bc$.
Key Concepts
Property A rational equation is an equation containing at least one rational expression. If it's a proportion, you can solve it using cross products: if $\frac{a}{b} = \frac{c}{d}$, then $ad = bc$. Explanation Think of these as fraction puzzles where 'x' is hiding! When two fractions are equal, you can cross multiply to get rid of the denominators and turn it into a regular equation. It’s a neat trick to un complicate things and find the hidden value of x. Examples To solve $\frac{7}{x} = \frac{4}{x 3}$, cross multiply to get $7(x 3) = 4x$, so $x=7$. To solve $\frac{x}{5} = \frac{2}{x+3}$, cross multiply to get $x(x+3) = 10$, so $x^2+3x 10=0$, which means $x=2$ or $x= 5$.
Common Questions
What is 'Rational equation' in Grade 9 math?
If it's a proportion, you can solve it using cross products: if $\frac{a}{b} = \frac{c}{d}$, then $ad = bc$. Explanation Think of these as fraction puzzles where 'x' is hiding!.
How do you solve problems involving 'Rational equation'?
Explanation Think of these as fraction puzzles where 'x' is hiding! When two fractions are equal, you can cross-multiply to get rid of the denominators and turn it into a regular equation.
Why is 'Rational equation' an important Grade 9 math skill?
In our example question, the denominators are 3 and $x$.. If we had found $x=0$ as a solution, we would have to reject it because you can't divide by zero!.