y-4=3(x-(-7))

The standard form of a linear equation is Ax+By=C.

Multiply -1 by -7.

y-4=3(x+7)

Apply the distributive property.

y-4=3x+3⋅7

Multiply 3 by 7.

y-4=3x+21

y-4=3x+21

Rewrite the equation with the sides flipped.

3x+21=y-4

Subtract y from both sides of the equation.

3x+21-y=-4

Move 21.

3x-y+21=-4

3x-y+21=-4

Subtract 21 from both sides of the equation.

3x-y=-4-21

Subtract 21 from -4.

3x-y=-25

3x-y=-25

Rewrite in Standard Form y-4=3(x-(-7))