Answer:
1 mi/hr
Step-by-step explanation:
Given that:
Speed in still water, s = 5 mi/hr
Let speed of current = x
Time = distance /speed
Upstream (subtract speed of current) = 5 - x
Upstream time = 8 / 5 - x - - - (1)
Downstream (add speed of current) = 5 + x
Downstream time = 12 / 5 + x - - - (2)
Equate (1) and (2)
8 / (5 - x) = 12/ (5 + x)
8(5 + x) = 12(5-x)
40 + 8x = 60 - 12x
40 - 60 = - 12x - 8x
-20 = - 20x
x = 1
Spwed of current = 1 mi/hr
As far a domain, you only care about the denominator and radicals.
f(x) = 2 - √x is the denominator, so it can't be 0.
Also x is under a radical, so x can't be negative.
Set the denominator equal to 0 to find the excluded values.
2 - √x = 0
-√x = -2
√x = 2
x = 4, so 4 is an excluded value
The domain is all real numbers greater than or equal to 0, except 4.
[0, 4) U (4, ∞)
0 ≤ x < 4 U x > 4
Answer:
(0, -2)
Step-by-step explanation:
y-intercept is the point at x = 0.
y = -3(0) - 2
y = -2
Answer:
x=0
Step-by-step explanation:
-5x-9=-3x-9
Add 5x to each side
-5x+5x-9=-3x+5x-9
-9 =2x-9
Add 9 to each side
-9+9 = 2x-9+9
0 =2x
Divide by 2
0/2 =2x/2
0 =x
Write each equation in y = mx + b form so that you can compare the slopes.
Perpendicular slopes are opposite reciprocals.
For example: 2/3 and - 3/2; 4/5 and -5/4; 1/2 and -2
I. y = -3x + 2 m = -3
II. y = 3/2 x + 1/2 m = 3/2
III. y = - 1/3x + 1/3 m = -1/3
IV. y = 1/3x + 9 m = 1/3 (I assuming this one had a typo in it since there is no equal sign.)
LETTER B is the answer I & IV
