Answer
b =10.5 and 3.5
Work Step by Step
As we know that the pair of points have y coordinate common so the distance between the two points can be found by getting the absolute value of the difference between the two non common y coordinate points.
Therefore, |b-7|=3.5
|x| =a so it can be x=-a or x=a
|b-7|=3.5
so, b-7 = 3.5 or b-7 = -3.5
b = 3.5+7 or b= -3.5+7
b=10.5 or b = 3.5
Therefore the possible values of b are 10.5 and 3.5.
