Answer:
A = 66 adults, C = 40 children
Step-by-step explanation:
We can set up a system of equations to find how many adults and how many children attended the concert, with A representing the adults and C representing the children:
[tex]A + C = 106\\4A+3.75C=414[/tex]
We can use the elimination method and multiply everything in the first equation by -4
[tex]-4(A+C=106)\\-4A-4C=-424\\4A+3.75C=414[/tex]
Once we add the values together, we're left with:
[tex]-0.25C = -10[/tex], where solving for C gives us C = 40
We can plug C into the first equation to find A: [tex]A+40=106[/tex], where solving for A gives us A = 66