We have to put values of domain to find range
[tex]\\ \ast\sf\longmapsto y=-4-x[/tex]
[tex]\\ \ast\sf\longmapsto D_R=[-6,2,7][/tex]
[tex]\\ \ast\sf\longmapsto y=-4-(-6)=-4+6=2[/tex]
[tex]\\ \ast\sf\longmapsto y=-4-2=-6[/tex]
[tex]\\ \ast\sf\longmapsto y=-4-7=-11[/tex]
Now
[tex]\\ \ast\sf\longmapsto R_R=[2,-6,-11][/tex]