Just plot the points on a graph.
Answer:
230 were sold at the door
170 were sold in advance
Step-by-step explanation:
*i dont know if this is the proper way to do it but it has the correct answer
x=at door y=in advance
x+y=400
3x+2y=1030
y=-x+400
2y=-3x+1030
y=-3/2x+515
-x+400=-3/2x+515
x=230 y=170
There’s no picture. Do it again and add the picture. Then we can see the scale
add the 2 numbers and then divide by 2
Distribute
y+10+c=z
minus y from both sides
10+c=z-y
minus 10 both sides
c=z-y-10