Understand the problem
Gather your resources
Come to an answering
Check your answer and present the solution
4(2x-4) = 16
4*2x - 4*4 = 16
8x - 16 = 16
8x = 16 + 16
8x = 32 / : 8
x = 4
Answer:
(A)
Length of DE = √17
EF = √18
DF = √17
(B) Slope of DE = 4
EF = 1
DF = 1/4
(C) Isosceles triangle.
Step-by-step explanation:
See attached image.
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