Taking the point directly under the center of the bridge as the origin,
x = 20t, y = 15t, z = 10
let s be thedistance between them at time t,
s^2 = (20t)^2 + (15t)^2 + 10^2 = 625t^2 + 100
2s ds/dt = 1250t
ds/dt = 625t/s
when t = 3, s = √(625*9+100) = 75.6637
ds/dt = 625*3/75.6637 = 24.78 m/s
Answer: hot dog = $1.75
<u>Step-by-step explanation:</u>
Let h represent hot dogs and c represent bags of chips.
Customer 1: 4h + 2c = 9.00 → 3(4h + 2c = 9.00) → 12h + 6c = 27.00
Customer 2: 5h + 3c = 11.75 → -2(5h + 3c = 11.75) → <u>-10h - 6c </u>= <u>-23.50</u>
2h = 3.50
<u> ÷2 </u> <u> ÷2 </u>
h = 1.75