Help solve these using the addition and multiplication properties of equality

#19
-4/5x=8
-4(x)/5=8
-4x/5=8
Multiply both sides by
-4x=8(5)
-4x=40
Divide both sides by -4
X= -10
#21
-4/3x+5=7
Multiply both sides by 3
-4/3x(3)+5(3)=7(3)
-4x+15=21
-4x=21-15
-4x=6
X=6/-4
X=-3/2