GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 09 Dec 2019, 16:27

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# What is the value of x[square_root] 3[/square_root]

Author Message
TAGS:

### Hide Tags

SVP
Status: It's near - I can see.
Joined: 13 Apr 2013
Posts: 1702
Location: India
GPA: 3.01
WE: Engineering (Real Estate)
What is the value of x[square_root] 3[/square_root]  [#permalink]

### Show Tags

28 Mar 2019, 22:19
2
00:00

Difficulty:

45% (medium)

Question Stats:

63% (01:33) correct 37% (01:47) wrong based on 49 sessions

### HideShow timer Statistics

What is the value of $$( x\sqrt{3} + y\sqrt{3} ) ^2$$ ?

1. $$2x + 2y = 20$$

2. $$x^2 + xy = 100 - y^2 - xy$$

_________________
"Do not watch clock; Do what it does. KEEP GOING."
Intern
Joined: 18 Oct 2018
Posts: 16
Re: What is the value of x[square_root] 3[/square_root]  [#permalink]

### Show Tags

31 Mar 2019, 11:48
AkshdeepS wrote:
What is the value of $$( x\sqrt{3} + y\sqrt{3} ) ^2$$ ?

1. $$2x + 2y = 20$$

2. $$x^2 + xy = 100 - y^2 - xy$$

Statement 1:
Simplify the equation -> x+y=10. Now we should rewrite the expression of the question stem to $$(\sqrt{3}(x+y))^2 = 3(x+y)^2$$.
Now just plug in the x+y=10 -> 300.

Statement 2:
Solving the expression of the question stem using the binomial theorem we get: $$3x^2 + 6xy +3y^2$$.
Next we move the $$y^2$$ and $$-xy$$ from the right side of the S2 equation to the left. Then multiply the whole equation by 3 to get the above equation -> $$3*100 = 300$$

Hence, statement D is correct.
Re: What is the value of x[square_root] 3[/square_root]   [#permalink] 31 Mar 2019, 11:48
Display posts from previous: Sort by