Algebra Rules - Addition and Subtraction
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The document discusses basic rules of algebra. It recaps terms like algebraic expressions and equations from the previous class. It then explains that the rules of addition and subtraction of algebraic terms are similar to numerical addition and subtraction, but the terms must be "like" terms, meaning they have the same variables. Unlike terms, with different variables, cannot be added or subtracted. It provides several examples to illustrate how to combine like terms through addition and subtraction.
Algebra Rules - Addition and Subtraction
- 1. Algebra - Recap In the last class you got to know about Terminologies of Algebra • Any real number with unknown term alphabets Algebraic Terms • Algebraic terms having same and different coefficients Like and Unlike Terms • Having one or more than one algebraic term combined with + or - Algebraic Expressions Equations • Two sides with = sign in between In this class you will learn about Basic rules of algebra. Edishta Resource Centre www.edishta.com
- 2. Algebra – Class 3 Basic Rules of Algebra 2 Edishta Resource Centre www.edishta.com
- 3. 3 Algebra - Rules addition subtraction Let’s just brush up them… 6 + 3 = 9 15 - 8 = 7 14 + 17 = 31 835 - 583 = 252 Same thing continues here also. But there are few rules to understand as we have unknown terms! Edishta Resource Centre www.edishta.com
- 4. 4 Algebra - Addition Do you remember the Chocolate example in the first You had x chocolates class? • You bought same x chocolates Now you have x + x = 2x chocolates • Correct? Let’s recall it Then your friend gives you 3x chocolates • So total is • 2x + 3x = 5x Edishta Resource Centre www.edishta.com
- 5. 5 Algebra - Addition So now you got the idea, right? It is just adding the numbers Let’s see more examples Then writing literal coef. with the answer 2x + 4x = 6x 12y + 5y = 17y 6a + 15a = 21a 84m + 12m = 96m 52p + 32p = 84p 19c + 94c = 113c 241d + d = 242d 751k + 469k = 1220k 2135u + 135u = 2270u 53xy + 24xy = 77xy pqr + 29qpr = 30pqr abcd + abcd = 2abcd Edishta Resource Centre www.edishta.com
- 6. 6 Algebra - Subtraction In subtraction also the basic rules remains the same. Subtract the numbers and write the unknown alphabet term in the answer with it Let’s see few examples to understand 6x - 4x = 2x 12y - 5y = 7y 16a - 15a = a 86m - 22m = 64m x - x = 0 (0 x = 0) 198c - 94c = 104c 21d - d = 20d 651k - 262k = 389k 2135u - 135u = 2000u 63xy - 44yx = 19xy 2pqr - pqr = qpr abcd - abcd = 0 Edishta Resource Centre www.edishta.com
- 7. Algebra – Observation The literal coef. are to be same for both terms for addition and subtraction. • i.e. Addition and subtraction Only for like terms You have learned in terminologies corollary that d=1d. • So such single terms are to be taken as 1 for addition and subtraction. Also you have learned ‘pqr’ = ‘qpr’ in algebra. • So addition and subtraction is possible in such cases. 0z = 0 and 0abcd = 0 i.e whatever with 0 is 0 itself. • No need to write the unknown term with 0 7 Edishta Resource Centre www.edishta.com
- 8. 8 Algebra – Unlike Term Rules What if the literal coeff. i.e. alphabets are not same? (unlike terms) x Mangoes y Oranges x + y Mangoes and Oranges So we are not adding numbers because both are different fruits It is common sense, isn’t it? Edishta Resource Centre www.edishta.com
- 9. Algebra - Unlike Term Rules So if the literal coeff. (alphabets) are not same (unlike) then we can not add nor subtract numbers Let’s familiarize them more clearly. 5x + 3y = 5x + 3y 41a + 12b = 41a + 12b 8pq+ 8pqr = 8pq + 8pqr 23qe – 5pe = 23qe – 5pe 9k – j = 9k – j p + q + r = p + q + r Remember the Mango + Orange when you see unlike terms Edishta Resource Centre www.edishta.com
- 10. 10 Algebra - Summary Addition Add the numbers Write the literal coeff. with the answer Subtraction Subtract the numbers Write the literal coeff. with the answer Rules Like terms can be added and subtracted Unlike terms can not be added nor subtracted. Observations 0 has no value so no need to have unknown term with it. 2x + 4y = 4y + 2x Terms can be interchanged but sign should be same Edishta Resource Centre www.edishta.com