Answer:
Only A, the first equation is true.
Step-by-step explanation:
A. (y + 6)(y – 7) + 42 = y² + 6y –7y – 42 + 42 = y² – y. This means A is true
B. (x + 3)(X – 8) = x² + 3x – 8x – 24 = x² – 5x – 24. This means B is false.
Answer:
Natasha charges $30 per house
Step-by-step explanation:
Profit = -126 + 30x
The cost of the cleaning supplies is 126
and the cost per house is 30
x = the number of houses cleaned.
Answer:
18x
Step-by-step explanation:
3x^2 - 27 = -18x
x^2 - 3x = -1x
-18x / -1x = 18x
3x^2 = 9
x^2 = 2x
Answer:
50
Step-by-step explanation:
The distance between the friends is changing at the constant rate of 50 mph.
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The equation for the distance in the westerly direction is ...
w = 30t . . . . . miles, where t is time in hours
The equation for the distance in the southerly direction is ...
s = 40t . . . . . miles, where t is time in hours
Then the total distance between the friends is ...
d = √((30t)² + (40t)²) = √(2500t²) = 50t . . . . miles, where t is time in hours
And the rate of change of distance is the derivative of this with respect to t:
dd/dt = 50 . . . . . . miles per hour
2400 I'm pretty sure that's correct
