1. The coefficient of x in the product (2-3) (
526) is
(a) 19
(5) - 19
(c) 15
(0) 6
2. 13x +ka? 8 = (3x-2)(x + 4) for all x, then the value of k is
(a) -2
(1) 12
(c) 10
(d) 8
3. The coefficient of in (3x++) (+)
is
(d) 2
(a) 3
(b) 1
(c) 4
4. If a = 3 + b3 prove that a-b-9ab27.
(a?-?) + (b2-c?) +(-a?!
5. Simplify:
(a - b)+(b-c)+(c-a)
1
6. If a + + 0, then the value of (a + 2) +-1
(a+2)
(a +2)
(a) 6
(6) 4
(c) 3
7. If a+++2=0, then the value of (o is
is
(d) 2
37
100
(d) 2
(c) 1
(b) -2
(a) 0
please answer fast please
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Answers
Answered by
1
Answer:
Step-by-step explanation:
The general term in the expansion of (2−x+3x
2
)
6
is
r!s!t!
6!
2
r
(−x)
s
(3x
2
)
t
, where r+s+t=6
=
r!s!t!
6
2
r
×(−1)
s
×3
t
×x
s+2t
,
where r+s+t=6
For the coefficient of x
5
, we must have
s+2t=5
But r+s+t=6
∴s=5−2t and r=1+t
where, 0≤r,s,t≤6
Now, t=0⇒r=1,s=5
t=1⇒r=2,s=3
t=2⇒r=3,s=1
Thus, there are three terms containing x
5
and coefficient of x
5
=
1!5!0!
6!
×2
1
×(−1)
5
×3
0
+
2!3!1!
6!
×2
2
×(−1)
3
×3
1
+
3!1!2!
6!
×2
3
×(−1)
1
×3
2
=−12−720−4320
=−5052.
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