While adding or subtracting,
We add subtract like terms
Add 3 𝑥 & 4𝑥
3𝑥 + 4𝑥
= 𝑥 (3 + 4)
= x × 7
= 7𝑥
Add 8xy & 2𝑥
8𝑥y + 2𝑥
Since 8𝑥y & 2𝑥 are unlike terms
We cannot add them
Add 8𝑥y, 4𝑥y & 2𝑥y
8𝑥y + 4𝑥y + 2xy
= xy (8 + 4 + 2)
= xy (14)
= 14𝑥y
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
(3𝑥 + 11) + (7𝑥 – 5)
We group like terms together
= (3x + 7x) + (11 − 5)
= 10𝑥 + 6
Add (3x + 11 + 8z) & 7x − 5
(3𝑥 + 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
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