# CLASS-8SUBTRACTION OF ALGEBRAIC FRACTION

SUBTRACTION OF ALGEBRAIC FRACTION –

SUBTRACTION OF ALGEBRAIC FRACTION WITH SAME DENOMINATOR

If algebraic fraction has the same denominator such as

x             y

------- and -------then we should subtract

z             z

the fraction as follows –

x              y             x - y

--------- - --------- = ----------

z              z               z

there are some examples are given below for your better understanding –

7             4

Example.1)  -------- - --------

5x           5x

7 - 4

=  -----------

5x

(After doing LCM of denominator of given fraction we find 5x)

3

=  ---------          (Ans.)

5x

9x              7y

Example.2)  ---------- - ----------

8a              8a

9x - 7y

=  ------------

8a

(After doing LCM of denominator of given fraction we find 8a)

9x - 7y

=  --------------         (Ans.)

8a

SUBTRACTION OF ALGEBRAIC FRACTION WITH DIFFERENT DENOMINATOR -

To add or subtract algebraic fractions that do not have the same denominator, first we have to find the LCM of their denominators and then proceed as in arithmetic.

w             y           (w X z) + (y X x)          wz + yx

-------- + -------- = ------------------- = -----------

x             z                (x X z)                   xz

8             5

Example.1)  -------- - --------

7x            6y

8 . 6x  -  5 . 7y

=  -----------------------

7x . 6y

(After doing LCM of denominator of given fraction we find 42xy)

48x - 35y

=  -----------------        (Ans.)

42xy

9a              7b

Example.2)  ---------- - ----------

8x              4y

(9a . y) - (7b . 2x)

=  ----------------------

8xy

(After doing LCM of denominator of given fraction we find 8xy)

9ay - 14bx

=  ---------------             (Ans.)

8xy