Last visit was: 18 Jul 2024, 21:01 It is currently 18 Jul 2024, 21:01
Toolkit
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
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

# In the system of equations above, what is the value of x ?

SORT BY:
Tags:
Show Tags
Hide Tags
Math Expert
Joined: 02 Sep 2009
Posts: 94407
Own Kudos [?]: 642118 [9]
Given Kudos: 85997
Math Expert
Joined: 02 Sep 2009
Posts: 94407
Own Kudos [?]: 642118 [3]
Given Kudos: 85997
Manager
Joined: 20 Dec 2013
Posts: 183
Own Kudos [?]: 291 [3]
Given Kudos: 35
Location: India
Manager
Joined: 21 Mar 2011
Status:GMATting
Posts: 96
Own Kudos [?]: 288 [1]
Given Kudos: 104
Concentration: Strategy, Technology
GMAT 1: 590 Q45 V27
Re: In the system of equations above, what is the value of x ? [#permalink]
1
Kudos
This is probably a sub-500 level question:

Multiply second equation by 2, change the sign and cancel y;
After that x can be determined.

Ans is (D) 1.
Director
Joined: 03 Feb 2013
Posts: 793
Own Kudos [?]: 2604 [0]
Given Kudos: 567
Location: India
Concentration: Operations, Strategy
GMAT 1: 760 Q49 V44
GPA: 3.88
WE:Engineering (Computer Software)
Re: In the system of equations above, what is the value of x ? [#permalink]
Bunuel wrote:
The Official Guide For GMAT® Quantitative Review, 2ND Edition

2x +2y =-4
4x + y = 1
In the system of equations above, what is the value of x ?

(A) -3
(B) -1
(C) 2/5
(D) 1
(E) $$1\frac{1}{4}$$

4x+y = 1
x+y = -2

Subtracting below equation from first => 3x = 3 => x = 1 - Option D)
Intern
Joined: 06 Jan 2014
Posts: 31
Own Kudos [?]: 28 [0]
Given Kudos: 23
Re: In the system of equations above, what is the value of x ? [#permalink]
seems sub 500...I haven't taken an official GMAT yet...I hope this is a 550 question I need the test to be as easy as possible!

I did it by taking the second equation...creating a "y=" and subbing
Intern
Joined: 11 Jul 2017
Posts: 2
Own Kudos [?]: 0 [0]
Given Kudos: 72
Re: In the system of equations above, what is the value of x ? [#permalink]
2x + 2y = -4
4x + y = 1

There is a easy method to get the answer in 20 seconds. To determine x, (difference of cross multiply coefficients of y with constants)/(difference of cross multiply coeff. of y with coeff. of x)

x = (2(1)-1(-4))/(2(4)-1(2)) = (2+4)/(8-2) = 6/6 = 1

Similarly we can determine y, (difference of cross multiply coefficients of x with constants)/(difference of cross multiply coeff. of x with coeff. of y)

y = (2(1)-4(-4))/(2(1)-4(2)) = (2-(-16))/(2-8) = (18/-6) = -3
GMAT Club Legend
Joined: 03 Jun 2019
Posts: 5307
Own Kudos [?]: 4220 [0]
Given Kudos: 161
Location: India
GMAT 1: 690 Q50 V34
WE:Engineering (Transportation)
Re: In the system of equations above, what is the value of x ? [#permalink]
Bunuel wrote:
The Official Guide For GMAT® Quantitative Review, 2ND Edition

$$2x +2y =-4$$

$$4x + y = 1$$

In the system of equations above, what is the value of x ?

(A) -3
(B) -1
(C) $$\frac{2}{5}$$
(D) 1
(E) $$1\frac{1}{4}$$

Problem Solving
Question: 41
Category: Algebra Algebra Simultaneous equations
Page: 67
Difficulty: 550

GMAT Club is introducing a new project: The Official Guide For GMAT® Quantitative Review, 2ND Edition - Quantitative Questions Project

Each week we'll be posting several questions from The Official Guide For GMAT® Quantitative Review, 2ND Edition and then after couple of days we'll provide Official Answer (OA) to them along with a slution.

We'll be glad if you participate in development of this project:
2. Please vote for the best solutions by pressing Kudos button;
3. Please vote for the questions themselves by pressing Kudos button;
4. Please share your views on difficulty level of the questions, so that we have most precise evaluation.

Thank you!

Given:
1. $$2x +2y =-4$$
2. $$4x + y = 1$$

Asked: In the system of equations above, what is the value of x ?

1. $$2x +2y =-4$$
2. $$4x + y = 1$$; $$8x + 2y = 2$$
(2) - (1)
6x = 6
x =1

IMO D
Intern
Joined: 16 Jul 2023
Posts: 7
Own Kudos [?]: 0 [0]
Given Kudos: 25
Location: United States (MA)
Concentration: Entrepreneurship, Strategy
GRE 1: Q179 V170
GPA: 3.1
Re: In the system of equations above, what is the value of x ? [#permalink]
Can someone explain me this in more detail

i did x+y = -2 [-; Minus] 4x +y = 1 which gave me 3x=-3 which gave me answer b) -1
Intern
Joined: 02 Aug 2020
Posts: 37
Own Kudos [?]: 20 [0]
Given Kudos: 249
Re: In the system of equations above, what is the value of x ? [#permalink]
Alextaller81

(x+y =-2) - (4x+y=1)
This will give you
-3x=-3
x=1

I got x-4x,in this you need to remember that the - sign is showing that 4x is negative and 4x>x so you can apply the rule that the bigger number is negative so the outcome will be negative

X-4x=-3,so in the end that’s how we get to -3x=-3.