Answer is 32
Here's why:
If these two lines are parallel, it means those 2 angles, (3x+11)° and (4x-21)°, are equal. So to find X, you need to set the equation
[tex]3x + 11 = 4x - 21 \\ x - 21 = 11 \\ x = 32[/tex]
If you want to check if it's the right answer, you can go back to those two angles, and if you put 32 instead of X, you'll get two identical numbers (that is 107°)
