Question

Admission to the movies costs $8 for adults and $4 for kids. The total bill for your entire extended family was $72. This scenario can be modeled by the equation 8a + 4k = 72. Which is not a possible combination of adults and kids?

3 adults and 12 kids

5 adults and 6 kids

7 adults and 4 kids

8 adults and 2 kids

Answer 1

just substitute the posibilities in the equation and check

Answer 2

for example the 1º posibility:
a=3, k=12
8*3+4*12=24+48=72 OK

do the same with the rest

Answer 3

thanks