Okay, lets say
B=booths
T=tables
P=people
without the numbers in your equation would look like this
B(P)+T(P)=100
So with everything plugged in your equation is
5(4)+T(6)=100
We need to solve for R, This is really simple.
The original expression is:
R (r1 + r2) = r1r2
To solve for a certain variable, we need to get this variable alone on one side of the equation and equate it with the other side.
In the given expression, to get R alone on one side we have to eliminate (r1 + r2).
In order to do this, we will divide both sides by (r1 + r2).
Doing this, we get the solution as follows:
R = (r1r2) / (r1 + r2)
The first graph is what i would think
