If 3x + 2y = 7 and 2x – y = 7, what is the value of x ?
A. 0
B. 1
C. 7/5
D. 21/11
E. 3
OA E
Source: GMAT Prep
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If 3x + 2y = 7 and 2x – y = 7, what is the value of x ?
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BTGmoderatorDC
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Brent@GMATPrepNow
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Let's use the elimination method to solve this systemBTGmoderatorDC wrote: ↑Mon Apr 05, 2021 7:27 pmIf 3x + 2y = 7 and 2x – y = 7, what is the value of x ?
A. 0
B. 1
C. 7/5
D. 21/11
E. 3
OA E
Source: GMAT Prep
Given:
3x + 2y = 7
2x – y = 7
Multiply both sides of the bottom equation by 2 to get the following equivalent equation:
3x + 2y = 7
4x – 2y = 14
Now add the two equations to get:
7x = 21
Solve: x = 3
Answer: E
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Scott@TargetTestPrep
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Solution:BTGmoderatorDC wrote: ↑Mon Apr 05, 2021 7:27 pmIf 3x + 2y = 7 and 2x – y = 7, what is the value of x ?
A. 0
B. 1
C. 7/5
D. 21/11
E. 3
OA E
Source: GMAT Prep
If we subtract the second equation from the first, we have:
x + 3y = 0
3y = -x
y = -x/3
Substituting this in the first equation, we have:
3x + 2(-x/3) = 7
9x - 2x = 21
7x = 21
x = 3
Answer: E
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