Question

(0.6a-0.5b)3+ (0.5b+0.7c)3-(0.6a+0.7c)3
factorise pls Solve this ​

Answer 1

Answer:

In+2.(n−1)+3(n−2)+.n.1

⇒tr=r(n−r)

∴ ∑

r=1

n

tr=∑

r=1

n

r(n−r)

=∑

r=1

n

(nr−r

2

)

=n.

2

n(n+1)

−

6

n(n+1)(2n+1)

=

2

n

2

(n+1)

−

6

(n

2

+n)(2n+1)

=

2

n

3

+n

−(

6

2n

3

+3n

2

+n

)=

6

n

3

−3n

2

+2n

Step-by-step explanation:

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