Given the system of equations One-third x minus two-thirds y = 7 and two-thirds x + 3 y = 11, which numbers can be multiplied by the equations to eliminate the x-variable? Check all that apply.
 –6 times the first and 3 times the second
 6 times the first and –3 times the second
 –3 times the first and 6 times the second
 3 times the first and –6 times the second
 2 times the first and –1 times the second