The function A(b) relates the area of a trapezoid with a given height of 10 and
one base length of 7 with the length of its other base.
It takes as input the other base value, and returns as output the area of the
trapezoid.
A(b) = 10 ⋅ b+7/2
Which equation below represents the inverse function B(a), which takes the
trapezoid's area as input and returns as output the length of the other base?