Help pleas y +12; y+(y+12); (y+(y+12))*4; 600; (y+(y+12))*4=600

1)y +12,y +12=0 ,y =-12. 2) y +(y +12)=y +y +12=0, 12+2*y =0, 2y =-12,y =-12/(2) ,y =-6. 3)(y +(y +12))*4=y +y +12)*4=0 ,48+8*y =0 , 8y =-48 ,y =-48/(8) ,y =-6. 4)(y +(y +12))*4=600=y +y +12)*4=600 ,48+8*y =600 ,8y =552 ,y =552/(8),y =69