S-10=B
S+1=2(B+1)
subtract the second equation from the first..
-11=-b-2
b=9
S=19
SUZY IS 10 YEARS OLDER THAN BILLY, AND NEXT YEAR SHE WILL BE TWICE AS OLD AS BILLY. HOW OLD IS SUZY NOW? HOW OLD IS BILLY?
1 answer
1 answer