Respuesta :
Answer:
147 adults and 11 children
Step-by-step explanation:
let x = the amount of adults
let y = the number of children
thus x + y = 158 total people who attend the movie
each adult cost $9 and each child costs $6 for a total cost of $1389 so
9x + 6y =1389
first lets solve for y so that we can use the substitution method..
x+y=158
to solve for y you must subtract x from both sides
x+y-x=158-x
y=158-x
now Let's use the substitution method
9x + 6(158-x)= 1389
9x + 6(158) + 6(-x) = 1389
9x+ 948 - 6x = 1389
3x+ 948= 1389
3x +948 - 948 = 1389 - 948
3x = 441
x = 147
back to the original equation of x + y = 158
147 + y = 158
147-147+y=158-147
y = 11
and finally
9(147) + 6(11) = 1389
1323 +66 = 1389