17^3 + 17^4 =

Jay@ManhattanReview: GMAT Instructor; Posts: 3008; Joined: Mon Aug 22, 2016 6:19 am; Location: Grand Central / New York; Thanked: 470 times; Followed by:34 members

Re: 17^3 + 17^4 =

by Jay@ManhattanReview » Thu Apr 23, 2020 10:13 pm

BTGModeratorVI wrote: ↑
Wed Apr 22, 2020 11:07 am
17^3 + 17^4 =

(A) 17^7
(B) 17^3*18
(C) 17^6*18
(D) 2*17^3 + 17
(E) 2*17^3 - 17

Answer: B
Source: Official guide

17^3 + 17^4 = 17^3 + 17*(17^3) = 17^3(1 + 17) = 17^3*18

The correct answer: B

Hope this helps!

-Jay
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GMAT/MBA Expert

Brent@GMATPrepNow: GMAT Instructor; Posts: 16207; Joined: Mon Dec 08, 2008 6:26 pm; Location: Vancouver, BC; Thanked: 5254 times; Followed by:1268 members; GMAT Score:770

Re: 17^3 + 17^4 =

by Brent@GMATPrepNow » Fri Apr 24, 2020 7:49 am

BTGModeratorVI wrote: ↑
Wed Apr 22, 2020 11:07 am
17^3 + 17^4 =

(A) 17^7
(B) 17^3*18
(C) 17^6*18
(D) 2*17^3 + 17
(E) 2*17^3 - 17

Answer: B
Source: Official guide

Jay's solution (above) is great.
Just for kicks though, I thought I'd show that we can factor 17^3 + 17^4 a different way and STILL arrive at the correct answer.

17^3 + 17^4 = 17^4[17^(-1) + 1]
= 17^4(1/17 + 1)
= 17^4(1/17 + 17/17)
= 17^4(18/17)
= 17^3 x 18

Answer: B

Cheers,
Brent

Brent Hanneson - Creator of GMATPrepNow.com

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GMAT/MBA Expert

Scott@TargetTestPrep: GMAT Instructor; Posts: 8086; Joined: Sat Apr 25, 2015 10:56 am; Location: Los Angeles, CA; Thanked: 43 times; Followed by:29 members

Re: 17^3 + 17^4 =

by Scott@TargetTestPrep » Fri Apr 24, 2020 8:17 am

BTGModeratorVI wrote: ↑
Wed Apr 22, 2020 11:07 am
17^3 + 17^4 =

(A) 17^7
(B) 17^3*18
(C) 17^6*18
(D) 2*17^3 + 17
(E) 2*17^3 - 17

Answer: B
Source: Official guide