Respuesta :

JustTasnim
expand the brackets first
-3y-12=21
add 12 
-3y=33
divide by -3
y= -11
gavinbradfordhart
Distribute negative 3 to y and 4. After distributing you should have -3y+-12=21. 21 plus 12 equals 33. 33 divides by negative 3 equals negative 11.