Answer:
3
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= 1/2x -2 is the equation for this line.
Answer:
34
Step-by-step explanation:
First we need to do 2/3*21, which equals 14 as 3 and 21 can be simplified to 1 and 7. 7 * 2/1= 14. Then we add the 20 to 14, 20+14= 34
