What is the area of the triangular base?
8 square feet
What is the length of edge DF?
4 feet
Answer:
1
Step-by-step explanation:
We need two points to find the slope
( -1,0) and ( 2,3)
We can use the slope formula
m = ( y2-y1)/(x2-x1)
= ( 3-0)/(2 - -1)
= (3-0) / ( 2+1)
= 3/3
= 1
The slope is 1
Answer:
Proof for 
Step-by-step explanation:
We are given that a, n, b, r and k are integers.
Also,

Since k divides a and b, we can write,
a = rk and b = sk, where r and s are integers.
Now, we have to prove that k divides r as well that is 
Putting value of a and b in the equation, we get:

Since, (r-sn) is an integer, k divides r.
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