Click below for Class 8 Algebraic Expressions and Identities NCERT solutions, Exemplar Solutions, worksheets and assignments, NCERT books, MCQs, easy to learn concepts and study notes and other study material
1. Expressions are formed from variables and constants.
2. Terms are added to form expressions. Terms themselves are formed as product of factors.
3. Expressions that contain exactly one, two and three terms are called monomials, binomials and trinomials respectively. In general, any expression containing one or more terms with non-zero coefficients (and with variables having non- negative exponents) is called a polynomial.
4. Like terms are formed from the same variables and the powers of these variables are the same, too. Coefficients of like terms need not be the same.
5. While adding (or subtracting) polynomials, first look for like terms and add (or subtract) them; then handle the unlike terms.
6. There are number of situations in which we need to multiply algebraic expressions: for example, in finding area of a rectangle, the sides of which are given as expressions.
7. A monomial multiplied by a monomial always gives a monomial.
8. While multiplying a polynomial by a monomial, we multiply every term in the polynomial by the monomial.
9. In carrying out the multiplication of a polynomial by a binomial (or trinomial), we multiply term by term, i.e., every term of the polynomial is multiplied by every term in the binomial (or trinomial). Note that in such multiplication, we may get terms in the product which are like and have to be combined.
10. An identity is an equality, which is true for all values of the variables in the equality. On the other hand, an equation is true only for certain values of its variables. An equation is not an identity.
11. The following are the standard identities:
(a + b) 2 = a2 + 2ab + b2 (I)
(a – b) 2 = a2 – 2ab + b2 (II)
(a + b) (a – b) = a2 – b2 (III)
12. Another useful identity is (x + a) (x + b) = x2 + (a + b) x + ab (IV)
13. The above four identities are useful in carrying out squares and products of algebraic expressions. They also allow easy alternative methods to calculate products of numbers and so on.
Latest CBSE News
- Concentration while studying is as important. Without concentration no matter how long you have been sitting for nothing could be learnt. Like many things concentration is not something you can achieve in a night or so you have to work on it for a while. Here are some tips from some studios that may help you to improve concentration and score good. Find your motivation: many students go on...
- Mathematics is the subject which is feared by most of the students. The problem becomes more critical now since the board exam is knocking the door. Usually students develop anxiety during mathematics exam. Usually mathematics is well thought-out as a subject of calculation actually involves logic, reasoning and imagination, moreover it also involves loads of stuffs related to calculations. This...
- Mobile phones, laptops, iPods, tablets, you name a gadget and it is available for use in today's technologically advanced era. Technology and these gadgets have become quite an integral part of our lives so to say. Every day a new gadget is being introduced and humans are getting more and more dependent on technology for their day to day needs. There is probably not a single activity left in the...
- All the CBSE students who are appearing for their board exams this year can breathe a sigh of relief. The Central Board of Secondary Education has decided to increase the number of questions given to the students with more internal choices. So now you don't have to worry about whether or not you will be able to solve all the questions. More choices within each question means that you can focus on...
- The central board of secondary education (CBSE) had started exams for 10th and 12th standards. The exams have started with the occupational subjects. The exams for the core subjects will start in few days time. The mathematics exam for class 10th is scheduled on 7th march. 18th March is scheduled date for the mathematics exam for class 12. Mathematics is a subject that is basically numerical...
- At the forefront of the board examinations for the core subjects, the cbse or central board of education had unconfined a review for the students against the fake news on the major social Medias. CBSE’s letter is a preventative endeavor to keep away from the circumstances was faced by the board in the last year throughout the board exams when gossip of leaking of question paper endlessly plagued...
- In a highly patriotic and important move to highlight one of the greatest men of our nation, Atal Bihari Vajpayee, the National Council of Educational Research and Training has introduced one of the poems written by this great leader in the 8th standard textbook. Must download these NCERT solutions for class 8 Hindi for free. The NCERT has taken this move with an aim to instil respect for the...