If \(2x + y = 18\) and \(3x = 17 + y,\) what is the value of \(x?\)

[Vincen]

If \(2x + y = 18\) and \(3x = 17 + y,\) what is the value of \(x?\)

A. 1
B. 4
C. 7
D. 9
E. 13

Answer: C

Source: Veritas Prep

[Brent@GMATPrepNow]

If \(2x + y = 18\) and \(3x = 17 + y,\) what is the value of \(x?\)

A. 1
B. 4
C. 7
D. 9
E. 13

Answer: C

Source: Veritas Prep

Let's use the elimination method...

GIVEN:
2x + y = 18
3x = 17 + y

Take 3x = 17 + y and subtract y from both sides to get: 3x - y = 17

We now have:
2x + y = 18
3x - y = 17

ADD the two equations to get: 5x = 35
Solve: x = 7

Answer: C

Cheers,
Brent