Q12 of 82 Page 126

If (3x – 1)7 = a7x7 + a6x6 + a5x5 + ………..+ a1x + a0, then let us write the value of a7 + a6 + a5 + …….. a0 (where a7, a6 ……………a0 are constants)

We have been given that,

(3x – 1)7 = a7x7 + a6x6 + a5x5 + … + a1x + a0


If we simply put x = 1 in the above equation,


(3(1) – 1)7 = a7(1)7 + a6(1)6 + a5(1)5 + …+ a1(1) + a0


⇒ a7 + a6 + a5 + … + a1 + a0 = (3 – 1)7


⇒ a7 + a6 + a5 + … + a1 + a0 = 27


⇒ a7 + a6 + a5 + … + a1 + a0 = 128


Thus, value of a7 + a6 + a5 + … + a1 + a0 = 128.

More from this chapter

All 82 →
12

If p(x) = x + 4, let us write the value of p(x) + p(–x).

 12

Let us write the remainder, if the polynomial x3 + 4x2 + 4x – 3 is divided by x.

 1

Let us calculate and write, which of the following polynomials will have a factor (x + 1)?

2x3 + 3x2 – 1

 1

Let us calculate and write, which of the following polynomials will have a factor (x + 1)?

x4 + x3 – x2 + 4x + 5