Algebra Formulas For Class 8
Here are some important algebra formulas for class 8:
- Algebraic expressions: An algebraic expression is a combination of variables, constants and arithmetic operations like addition, subtraction, multiplication and division.
- Algebraic identities:a. (a + b)^2 = a^2 + 2ab + b^2 b. (a – b)^2 = a^2 – 2ab + b^2 c. (a + b)(a – b) = a^2 – b^2 d. (a + b)^3 = a^3 + 3a^2b + 3ab^2 + b^3 e. (a – b)^3 = a^3 – 3a^2b + 3ab^2 – b^3
- Linear equations in one variable: A linear equation in one variable is an equation of the form ax + b = 0, where x is the variable and a and b are constants.a. Solving linear equations: To solve a linear equation in one variable, isolate the variable on one side of the equation by performing the same operation on both sides.b. Cross-multiplication method: To solve equations of the form ax = b or a/x = b, cross-multiply to obtain an equation in the form ax = b or a = bx.
- Quadratic equations: A quadratic equation is an equation of the form ax^2 + bx + c = 0, where x is the variable and a, b and c are constants.a. Quadratic formula: The solutions of a quadratic equation can be obtained using the quadratic formula:x = (-b ± √(b^2 – 4ac)) / 2ab. Factorization method: A quadratic equation can be solved by factorizing it into two linear factors.
- Exponents: An exponent is a number that represents the number of times a base number is multiplied by itself. For example, 2^3 = 2 x 2 x 2 = 8.a. Laws of exponents:i. a^m x a^n = a^(m+n) ii. a^m / a^n = a^(m-n) iii. (a^m)^n = a^(mn) iv. a^0 = 1 v. a^(-m) = 1/a^m
- Polynomials: A polynomial is an algebraic expression consisting of one or more terms.a. Degree of a polynomial: The degree of a polynomial is the highest power of the variable in the polynomial.b. Adding and subtracting polynomials: To add or subtract polynomials, add or subtract the coefficients of like terms.
These are some of the important algebra formulas for class 8. It is important to practice these formulas and solve problems to gain a better understanding of algebra.
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