Question:
How many terms are there in the expansion of (1 + 2x + x2)5 + (1 + 4y + 4y2)5 ?
How many terms are there in the expansion of (1 + 2x + x2)5 + (1 + 4y + 4y2)5 ?
Options:
- 20
- 12
- 22
- 21
- 20
- 12
- 22
- 21
Correct Answer: c)
Explanation:
Gi√en expansion,
(+x2 +x2)” + (1+4y+42)° i
5 5
CHE (CR)
‘ = (1+) + (1+ 2y)1°
.”. Total number of terms in gi√en expansion
‘ —(10+1)+(10+1)=x2 ‘
27 !
n-1
(b)y(n+2).2 ‘
‘
Gi√en expansion,
(+x2 +x2)” + (1+4y+42)° i
5 5
CHE (CR)
‘ = (1+) + (1+ 2y)1°
.”. Total number of terms in gi√en expansion
‘ —(10+1)+(10+1)=x2 ‘
27 !
n-1
(b)y(n+2).2 ‘
‘