According to class 7th chapter 4 maths, an extraneous solution is a solution that appears to work in the process of solving an equation but doesn't satisfy the original equation. They often arise from operations that introduce restrictions, like division by zero or square roots of negative numbers. To avoid extraneous solutions, always check the solutions you find by substituting them back into the original equation. If the substituted value doesn't satisfy the equation, it's not a valid solution. Practice class 7th chapter 4 maths solutions to get in-depth understanding of the concepts.