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.
Standard Form is ax + by = c, where a, b, and c are not fractions and a is not negative.
So, you can go through each of your options to see which ones work with those rules.
A. 2.5x + 3y = 12 No, this is not in Standard Form. 2.5 can be rewritten as 2<span>

, menaing A is a fraction, which you can't have.
B. -10x - 3y = 1 No, this is not in Standard Form. A is -10, but A can't be negative.
C. 2x + 3y = 12 Yes, this is in Standard Form. It follows all of the rules.
D. 5x + 5y = 10 Yes, this is in Standard Form. It follows all of the rules.
So,
C and
D are both written in Standard Form.
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The number is 36 because 1,2,3,4,6,9,12,16,24,36 and that is 10 factors
Raising a whole number to a power means:
Take (a number of things) a number of times, and then possibly
take that big number of things a number of times again.
Raising a fraction to an exponent means:
Take a piece of (a piece of one thing), and then possibly
take just a piece of that smaller piece.