System of Equations
Let:
x = number of people that can be seated at a table
y = number of people that can be seated at a booth
The first plan consists of 23 tables and 10 booths and then 228 people could be seated, thus:
23x + 10y = 228
The second plan consists of 12 tables and 12 booths and that way 180 people could be seated, thus:
12x + 12y = 180
The method of elimination requires equating the coefficients of one variable and eliminating it by adding the equations.
Multiply the first equation by 12:
276x + 120y = 2736
Multiply the second equation by -23:
-276x - 276y = -4140
Add the last two equations (the variable x cancels out):
120y - 276y = 2736 - 4140
Simplifying:
-156y = -1404
Dividing by -156:
y = -1404/(-156)
y = 9
Substitute this value in the first equation:
23x + 10(9) = 228
Operate:
23x + 90 = 228
Subtract 90:
23x = 138
Divide by 23:
x = 138/23
x = 6
Every table can seat 6 people, and every booth can seat 9 people
