from the information given you can form two linear equations.
Red kite: Y = 8x + 100
Blue Kite: Y = 5x + 180
you are looking for where these two lines intersect on a graph.
Each equation gives you a value of y so you can take one and put it in the place of the other
Ex., 8x + 100 = 5x +180
rearrange this and you get 3x - 80 = 0
then isolate x:
1) 3x = 80
2) x = 80/3
3) x = 26.7
Now, put your X value into either of the original equations to find Y
Y = 8x + 100
Y = 8(26.7) + 100
Y = 313.6
to check your answer you can do a simple left side right side check
313.6 = 5(26.7) + 180
313.6 = 133.5 + 180
313.6 = 313.5
** this counts as correct, the difference in decimal is due to rounding
