Please help I’m really stuck!!

Step 1: Solve for one variable

---I will be using the first equation and solving for a.

a + c = 405

a = 405 - c

Step 2: Substitute into the other equation

---Now that we have a value for a, we can substitute that value into the second equation. Then, we can solve for c.

12a + 5c = 3950

12(405 - c) + 5c = 3950

4860 - 12c + 5c = 3950

-12c + 5c = -910

-7c = -910

c = 130

Step 3: Plug back into the first equation

---We now know one variable, which means we can plug back into our first equation and solve for the other.

a = 405 - c

a = 405 - 130

a = 275

275 adults, 130 children

Hope this helps!

18

step-by-step explanation:

draw the shape and you will see that f and k are actually at adjacent vertices (points of the hexagon that are neighboring).   so find the distance between (1,2) and (4,2).   that is easy since (1,2) and (4,2) is just a vertical distance to count, which is 3.   it is a regular polygon which means all sides are congruent.   you have 6 sides (hexa) so multiply 6 by 3 to receive 18.