Solve the following quadratic equations by factorizing. Show all your steps.
Solve: $x^2 + 7x + 12 = 0$
Solve: $x^2 + 3x - 10 = 0$
Solve: $x^2 - 8x + 15 = 0$
Solve: $x^2 - 5x - 24 = 0$
Solve: $x^2 - 49 = 0$
Solve: $2x^2 + 7x + 3 = 0$
Solve: $3x^2 - 13x + 4 = 0$
Solve: $x^2 + 10x = -21$
Solve: $4x^2 + 8x - 5 = 0$
Solve: $6x^2 - x - 2 = 0$