You take
7.25 (10)+5.5p=105.5
72.5+5.5p=105.5
To make the equation easier multiply the whole equation by ten like this
(72.5+5.5p=105.5)10 that equals
725+55p=1055
Then subtract 725 to both sides
725+55p=1055
-725 -725
____ _____
55p=330
Then divide by 55 on both sides and that equals 6 so 6 people bought tickets
In order to find b1 from your formula stated we need to do few calculations
A=hb1+hb2, as you wee I multiply h with both bases( b1 and b2)
I will subtract hb2 from both sides
hb1=A-hb2
now I will divide my new expression by h
b1=(A-hb2)/h
