Question 158377
8A+5C=439
A+C=71 OR A=71-C
8(71-C)+5C=439
568-8C+5C=439
-3C=439-568
-3C=-129
C=-129/-3
C=43 CHILDREN TICKETS SOLD.
A+43=71
A=71-43
A=28 ADULT TICKETS SOLD.
PROOF:
8*28+5*43=439
224+215=439
439=439