/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Q.33 use the Binomial Theorem to find... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

use the Binomial Theorem to find the indicated coefficient or term.

The coefficient of x7 in the expansion of (2x +3)9

Short Answer

Expert verified

The coefficient of x7 is 4608

Step by step solution

01

. Given information

Here (2x+3)9 is given.

we have to find out the coefficient of the term x7

02

. Expansion of  (2x+3)9 using The Binomial Theorem

According to the binomial theorem

Letxandaberealnumbers.Foranypositiveintegern,wehave(x+a)n=n0xn+n1axn-1+n2a2xn-2+.......+njajxn-j+.....+nnan

Based on this we can expand, here a=1 and n=9

localid="1647339902877" (2x+3)9=90(2x)9+91(1)(2x)9-1+92(1)2(2x)9-2+93(1)3(2x)9-3+......+98(1)8(2x)9-8+9919=90(2x)9+91(2x)8+92(2x)7+93(2x)6+......+98(2x)1+99

03

Step 3. Description of finding the coefficient of x7

From the expanded form of (2x+3)9 we get a coefficient of x7

then the coefficient of x7 is

92(2)7(1)2,whichisequalto9!2!7!×27=9×8×7!2×1×7!×128=4608

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Study anywhere. Anytime. Across all devices.