2. Algebraic expression A Combination of constants and variables connected by the signs of fundamental operations of addition,subtraction, division and multiplication is called an algebraic expression. Terms Various parts of an algebraic expression which are seprated by the signs+ or – are called the ‘terms’ of the expression. Illustration-3y+4x is an algebraic expressions having 3y and 4x as terms
3. Types of Algebraic expressions Monomial- an algebraic expression containing only one term Example-3x , 4z, 2y ,5t are monomials. Binomial-An algebraic expression containing two terms. Example-3y+5x , 4z-6y , 2x+6x are binomials. Trinomial-An algebraic expression containing three terms. Example-3x+4z-2w , 5y+4z-3x, 4z-1y+10x are trinomials. Quadrinomial-An algebraic expression containing four terms. Example-3y+x+6y-7x , 4z+5z-6x+10x are quadrinomials.
4.
5. In the term -4xyz , the numerical factor is -4 and x, y , z are literal factors.
6.
7.
8. Addition of negative like terms. Step1-Obtain all like terms. Step2-Obtain the sum of the numerical coefficients (without the negative sign) of all like terms. Step3-Write an expression as a product of the number obtained is step2, with all the literal coefficients preceded by a minus sign. Step4-The expression obtained in step3 is the required sum. Add -7xy,-3xy,-9xy The sum of the numerical coefficients(without the negative sign) is 7+3+9=19 Hence -7x,-3xy,-9xy=-19xy
9. Operations On Algebraic Expression. Addition of positive terms Procedure- Obtain all like terms. Find the sum of the numerical coefficients of all like terms. Write the required sum as a like term whose numerical coefficients is the numerical obtained in step 2 and literal factors of the given like terms. Illustration-Add 4xy ,12xy and 3xy Solution- The sum of the numerical coefficients of the given like terms is 4+12+3=19. Thus the sum of the given like terms is another like term whose numerical coefficient is 19. Hence,4xy+12xy+3xy=19xy. Aliter-the sum of the given like terms can also be obtained by using the distributive property of multiplication over addition as discussed below- 4xy+12xy+3xy=(4+12+3)xy=19xy
10. Addition of +ive and –ive like terms Step1-Collect all +ive like terms and find their sum. Step2-Collect all the -ive like terms and find their sum. Step3-Obtain the numerical coefficients(without -ive sign) of like terms obtained in steps1 and 2. Step4-Subtract the numerical coefficient in step2 from the numerical coefficient in steop1.Write the answer as a product of this number and all the literal coefficients. Add 4xy,8xy,-2xy 4xy+8xy- 2xy (4xy+8xy)-2xy (Collecting +ive and –ive like terms together) 12xy-2xy=10xy
11. Addition of algebraic expression with an unlike terms like In adding algebraic expression containing like and unlike terms we collect different groups of like terms and find the sum of like terms in each groups by the methods discussed below- 1)Horizontal method 2)Column method (7x+4)+(3x-1) 7x+4 =(7x+3x)+(4-1) +3x-1 =10x+3 =10x+3
12. Subtraction of algebraic expression To subtract an algebraic expression from another we should change signs(from + to – or from – to+)of all the expression which is to be subtracted and then the two expressions are added. Subtract 5x from 9x 9x-5x=4x Subtract x+y from 5x-3y (5x-3y)-(x+y) 5x-3y-x-y (5x-x)-3y-y 4x-4y
