Answer:
Step-by-step explanation:
What equation??
Answer:
-390 mph
Step-by-step explanation:
Let a and b represent, respectively, the distances of A and B from the airport. The distance d between the planes is then given by the Pythagorean theorem as ...
d² = a² + b²
Differentiating with respect to time, we have ...
2d·d' = 2a·a' +2b·b'
Solving for d', we get ...
d' = (a/d)a' +(b/d)b'
The value of d at the time of interest is ...
d = √(a² +b²) = √(30² +40²) = √2500 = 50
Then the rate of change of separation is ...
d' = (30/50)(-250 mph) +(40/50)(-300 mph) = (-150 -240) mph
d' = -390 mph
The distance between planes is decreasing at 390 miles per hour.
Answer:
1. x=1
2. x=7
Step-by-step explanation:
1. -8(1+4x)+7x=-25-8x
-8-32x+7x=-25-8x
8x-32x+7x=-25+8
-17x=-25+8
-17x=-17
2. -5+6(x-7)=-40+5x
-5+6x-42=-40+5x
-47+6x=-40+5x
x=47-40
x=7
Answer:
32.
Step-by-step explanation:
This is an arithmetic sequence with first term a1 = -6 and common difference 2.
an = a1 + d(n - 1)
a20 = -6 + 2(20-1) = 32
