|3x-y+8|与(2x+y-18)²互为相反数,则3x+y=?

|3x-y+8|与(2x+y-18)²互为相反数,则3x+y=?
|3x-y+8|与(2x+y-18)²互为相反数,则3x+y=?

|3x-y+8|与(2x+y-18)²互为相反数,则3x+y=?
|3x-y+8|与(2x+y-18)²互为相反数
则|3x-y+8|+(2x+y-18)²=0
则3x-y+8=0①
2x+y-18=0②
①+②,得5x-10=0,解得x=2
代入①,解得y=14
则3x+y=6+14=20