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# Exponent Algebra; Help!!

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Intern
Joined: 09 Jun 2017
Posts: 27
Location: United States (CA)
GMAT 1: 730 Q49 V41
GPA: 3.43
WE: Analyst (Real Estate)

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17 Oct 2017, 18:27
Can someone please explain to me the following:

[15^x + 15^x(15^1)] => (15^x)(1 + 15)

This is in the solution section of a question from an MGMAT practice CAT and I can't for the life of me figure out how they arrived at the second part algebraically.

Intern
Joined: 17 Aug 2017
Posts: 7
Location: India
Concentration: Technology, Finance
Schools: HBS '20, Booth '20, IIMC
GMAT 1: 740 Q49 V42
GPA: 3.91

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17 Oct 2017, 19:41
mcdo wrote:
Can someone please explain to me the following:

[15^x + 15^x(15^1)] => (15^x)(1 + 15)

This is in the solution section of a question from an MGMAT practice CAT and I can't for the life of me figure out how they arrived at the second part algebraically.

Take 15^x common and you will get the 2nd part.
Math Expert
Joined: 02 Sep 2009
Posts: 51280

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17 Oct 2017, 20:21
mcdo wrote:
Can someone please explain to me the following:

[15^x + 15^x(15^1)] => (15^x)(1 + 15)

This is in the solution section of a question from an MGMAT practice CAT and I can't for the life of me figure out how they arrived at the second part algebraically.

Please post complete question. Thank you.
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Director
Joined: 30 Jan 2016
Posts: 839
Location: United States (MA)

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17 Oct 2017, 22:41
1
mcdo wrote:
Can someone please explain to me the following:

[15^x + 15^x(15^1)] => (15^x)(1 + 15)

This is in the solution section of a question from an MGMAT practice CAT and I can't for the life of me figure out how they arrived at the second part algebraically.

They took out 15^x outside the brackets:
$$(15^x+15^x * 15) = 15^x (1 + 15) = 15^ x * 16$$
_________________

Non progredi est regredi

Intern
Joined: 09 Jun 2017
Posts: 27
Location: United States (CA)
GMAT 1: 730 Q49 V41
GPA: 3.43
WE: Analyst (Real Estate)

### Show Tags

18 Oct 2017, 18:30
Masshole wrote:
mcdo wrote:
Can someone please explain to me the following:

[15^x + 15^x(15^1)] => (15^x)(1 + 15)

This is in the solution section of a question from an MGMAT practice CAT and I can't for the life of me figure out how they arrived at the second part algebraically.

They took out 15^x outside the brackets:
$$(15^x+15^x * 15) = 15^x (1 + 15) = 15^ x * 16$$

Ohhhhhhhh - thank you!
Re: Exponent Algebra; Help!! &nbs [#permalink] 18 Oct 2017, 18:30
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