Check sibling questions

While adding or subtracting,

We add subtract like terms

 

Add 3 π‘₯ & 4π‘₯

 3π‘₯ + 4π‘₯

= π‘₯ (3 + 4)

= x × 7

= 7π‘₯ 

 

Add 8xy & 2π‘₯

8π‘₯y + 2π‘₯  

Since 8π‘₯y & 2π‘₯ are unlike terms

We cannot add them

 

Add 8π‘₯y, 4π‘₯y & 2π‘₯y

8π‘₯y + 4π‘₯y + 2xy

= xy (8 + 4 + 2)

= xy (14)

= 14π‘₯y     

 

Subtract 4n from 7n

7n − 4n

= n(7 − 4)

= n × 3

= 3n

 

Subtract 5ab from 11ab

11ab − 5ab

= ab (11 − 5)

= ab × 6

= 6ab

 

Now,

Suppose our expressions are bigger

 

Add 3x + 11 & 7x − 5

(3π‘₯ + 11) + (7π‘₯ – 5)

We group like terms together

= (3x + 7x) + (11 − 5)

 = 10π‘₯ + 6

 

Add (3x + 11 + 8z) & 7x − 5

(3π‘₯ + 11 + 8z) + (7x − 5)

= (3x + 7x) + (11 − 5 ) + 8z

= x (3 + 7) + (6) + 8z

= 10x + 6 + 8z

= 10x + 8z + 6   

 

  Subtract (a − b) from 3a − b + 4

(3a − b + 4) − (a − b)

= 3a − b + 4 − a + b

= (3a − a) + (−b + b) + 4

= (3a − a ) + (b − b) + 4

= 2a  + 0 + 4

= 2a + 4

Learn in your speed, with individual attention - Teachoo Maths 1-on-1 Class

Ask a doubt
Davneet Singh's photo - Co-founder, Teachoo

Made by

Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 13 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.