Answer:
The speed in still water is 5 miles per hour.
Step-by-step explanation:
distance with current = 90 miles
distance against current = 10 miles
speed in still water = s
speed of current = 4 mph
speed with current = s + 4
speed against current = s - 4
time = t
speed = distance/time
distance = speed * time
With current:
90 = (s + 4) * t
Against the current:
10 = (s - 4) * t
We have a system of equations:
90 = (s + 4) * t
10 = (s - 4) * t
90 = ts + 4t
10 = ts - 4t
Subtract the second equation from the first equation.
80 = 8t
10 = t
t = 10
10 = t(s - 4)
10 = 10(s - 4)
1 = s - 4
s = 5
Answer: The speed in still water is 5 miles per hour.
plug in -4 in for x. then solve.
h(-4)=1/2(-4)-1
h(-4)= -3
Answer:
B
Step-by-step explanation:
let f(x) = y and rearrange making x the subject
y = 
( multiply both sides by 7 to clear the fraction )
7y = x + 2 ( subtract 2 from both sides )
7y - 2 = x
Change y back into terms of x with x the inverse function, that is
p(x) = 7x - 2
Trapezoids always have 4 sides, so this is true. All rhombuses have parallel sides, so B is true also. A trapezoid has two sides that are not parallel, so C is not true. (remember, you only have to find one instance where your statement is false for it to be false) And for D, all rhombuses are kite-shaped so D is not true. A and B are true. Hope this helps. :)
