Need help solving and justifying equation = please and Thank you

Question

The Equation -7(x-4) = 49

-7x + 28 = 49 (reason or justification)

-7x + 28-28 = 49 - 28 (reason or justification)

-7x = 21 (reason or justification)

-7x/-7 = 21/-7 (reason or justification)

x= -3 (Distributive property)

Answer 1

The Equation -7(x-4) = 49

-7x + 28 = 49 (DISTRIBUTIVE property - distributed the (-7) into the (x-4))

-7x + 28-28 = 49 - 28 (SUBTRACTION property - subtracted 28 from both sides))

-7x = 21 (simplified each side 28 - 28 = 0, and -7x + 0 = -7x; 49 - 28 = 21) -

in geometry we call this the SUBSTITUTION property, because you are substituting (-7x) for the (-7x+28-28) above; and substituting 21 in place of (49-28) form the line above))

-7x/-7 = 21/-7 (DIVISION property - divided both sides by (-7))

x= -3 (simplified each side,

 in geometry we call this the SUBSTITUTION property because you are substituting "x" for (-7x/-7); and substituting -3 in place of 21/(-7))