Respuesta :
x = -3
Pull out the like terms: -7x - 21 = -7 × ( x + 3)
Solve: -7 = 0
Solve: x + 3 = 0
Subtract 3 from both sides of the equation
So, x = -3
Pull out the like terms: -7x - 21 = -7 × ( x + 3)
Solve: -7 = 0
Solve: x + 3 = 0
Subtract 3 from both sides of the equation
So, x = -3