OG详解-OG6 数学2 Q21

The correct answer is 1,677. Adding the first equation to the second equation in the given system yields (x-2)+(x-2)+(-4)(y+7 +4(y+7) = 117+442, or 2(x-2) = 559.  Multiplying both sides of this equation by 3 yields 6 (x-2) = 1,677. Therefore, the value of 6 (x-2) is 1,677.