Answer:
I think it is add 11 both sides? If it is wrong i am sooooo sorry
Step-by-step explanation:
Answer:
Speed of plane in still air: 490 mile/hour
speed of wind: 70 mile/hour
Step-by-step explanation:
still speed = x wind speed = w
with wind: speed = still + wind
(x+w) * 3 = 1680 ...a
against wind: speed = still - wind
(x-w) * 4 = 1680 ...b
b-a ... 4x-4w-3x-3w = 0
x-7w = 0
x = 7w
substitution: (7w+w)*3 = 1680 8w = 560 wind speed (w) = 70
still speed (x) = 7w = 490 mile/hour
y/x = k
6.4/4 = 1.6
11.2 / 7 =1.6
16/10 = 1.6
20.8 /13 =1.6
This is a direct variation and the constant is 1.6
y=1.6x