angle ABE is equivalent
to the whole angle, and it measures 2b.
while the angle ABF is only a portion of angle ABE, and it
measure 7b - 24.
since we know the measure of the whole angle and a part of
the angle, we can then subtract to find the left over angle (angle EBF), so
Angle EBF = Angle ABE - Angle ABF
Angle EBF = 2b – (7b –
24)
Angle EBF = 24 – 5b
