Ben's meal cost $0.45 less than Sami's.
B = S - .45
Louis's meal cost twice as much as Ben's.
L = 2B = 2(S - .45)
the bill came to $9.25
S + B + L = 9.25
substitute for B and L, then solve for S ... finding B and L will then be easy.
The equation says to solve for Sami so we'll use S in the equation S+(S-0.45)+2(S-0.45)=9.25 use distributive property S+S-0.45+2S-0.90=9.25 now collect the variables 4S-1.35=9.25 now isolate the variable by adding 1.35 to both sides now you have 4S=10.60 now to get the variable by itself divide both sides by 4 now you have S=2.65 we know Ben paid 0.45 less then Sam so B= 2.65-0.45=2.20 and louis paid twice as much as Ben so L=2(2.20)=4.40 now add S+B+L 2.65+2.20+4.40=9.25