Answer: x = 8
Step-by-step explanation: In this problem, we're given a diagram and we're asked to find the value of x that would make a || b.
We can see that the angles that are marked
in the diagram are alternate interior angles.
Therefore, in order for line a to be parallel to line b, these angles
must be congruent so we can setup the equation 7x - 40 = 2x.
Solving from here, we subtract 7x from both sides to get -40 = -5x.
Then divide both sides by -5 to get x = 8.
So the value of x that would make a || b is 8.
We can check our answer by plugging 8 in for x in each angle
and we will find that this value makes the angles congruent.