Download NCERT Solutions for Class 8 Maths PDF format. Exemplar problems and its answers are also available to download. Solutions of all questions are described completely. If some one is still facing problem to understand the solution any question, please specify through “FORUM” section. Solutions of all exercises are given as separate PDF files. Assignments, Notes, Sample Papers, Chapter test and other study material will be uploaded very soon. Please give feedback and suggestions to improve the contents and quality if possible.
Buy Books & Solutions Online
Main point to be remembered
1. Rational numbers are closed under the operations of addition, subtraction and multiplication.
2. The operations addition and multiplication are (i) commutative for rational numbers. (ii) associative for rational numbers.
3. The rational number 0 is the additive identity for rational numbers.
4. The rational number 1 is the multiplicative identity for rational numbers.
5. The additive inverse of the rational number exists.
6. The reciprocal or multiplicative inverse of the rational number exists.
7. Distributivity of rational numbers: For all rational numbers a, b and c, a(b + c) = ab + ac and a(b – c) = ab – ac
8. Rational numbers can be represented on a number line.
9. Between any two given rational numbers there are countless rational numbers. The idea of mean helps us to find rational numbers between two rational numbers.
1. An algebraic equation is an equality involving variables. It says that the value of the expression on one side of the equality sign is equal to the value of the expression on the other side.
2. The equations we study in Classes VI, VII and VIII are linear equations in one variable. In such equations, the expressions which form the equation contain only one variable. Further, the equations are linear, i.e., the highest power of the variable appearing in the equation is 1.
3. A linear equation may have for its solution any rational number.
4. An equation may have linear expressions on both sides. Equations that we studied in Classes VI and VII had just a number on one side of the equation.
5. Just as numbers, variables can, also, be transposed from one side of the equation to the other.
6. Occasionally, the expressions forming equations have to be simplified before we can solve them by usual methods. Some equations may not even be linear to begin with, but they can be brought to a linear form by multiplying both sides of the equation by a suitable expression.
7. The utility of linear equations is in their diverse applications; different problems on numbers, ages, perimeters, combination of currency notes, and so on can be solved using linear equations.