Respuesta :

you first combine like terms -1x and -4x to make the equation 21=6-5x then subtract 6 from itself to cancel it out and from 21, 15=5x where x= 3
well first you add like terms
21=6-1x-4x
21=6-5x
now, move your x value in front of the =
21=6-5x
-5x   -5x
21-5x=6
next, move the 21 to behind the =
21-5x=6
-21    -21
-5x=6-21
then do 6-21, which equals -15, so
-5x=-15
next, divide both sides by -5
-5x=-15
-5    -5
x=3