1.395+x=864 x=864-395 x=469 2.z+213=584 z=584-213 z=371 3.300-y=206 y=300-206 y=94 4.t-307=308 t=308+307 t=615 5.166=m-34 m=166+34 m=200 6.59=81-k k=81-59 k=22