Answer:
9 mph = the speed in still water
Step-by-step explanation:
Let r = the speed in still water
Then the speed going down stream is r + 3
and the speed going upstream is r - 3
d = rt or t = d/r
time going downstream is 16/(r + 3) and time going upstream is 16/(r - 3)
The total time was 4 hours, so
Multiply thru the equation by (r + 3)(r - 3)
Then 16(r - 3) + 16(r + 3) = 4(r + 3)(r - 3)
16r - 48 + 16r + 48 = 
- 36
- 36 = 32r
- 32r - 36 = 0
4(r - 9)(r + 1) = 0
r = 9 or -1
But a rate of speed cannot be negative, so x ≠ -1
So, r = 9 mph = the speed in still water
Answer:
Step-by-step explanation:
R = report length
R = 40 + (3/8)R + (1/3)R
3/8 = 3*3/8*3 = 9/24
1/3 = 8*1 / 3*8 = 8/34
R = 40 + (9/24)R + (8/24)R
R = 40 + (17/24)R Subtract 17/24 from the left
R-17/24 R = 40
7/24 R = 40 Multiply both sides by 24
7R = 40 * 24
7R = 960 Divide by 7
R = 960/7
R = 137.1 which breaks the rounding rule and becomes 138 because something has to be typed on page 138
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Answer:
a. 3
b. -22
c. -2
d. -2
e. 5a + 8
f. a² + 6a + 3
Step-by-step explanation:
Calculate the answers by substituting the values inside of the parenthesis for 'x':
a. f(1) = 5(1) - 2 = 3
b. f(-4) = 5(-4) - 2 = -22
c. g(-3) = (-3)² + 2(-3) - 5 = 9 - 6 - 5 = -2
d. g(1) = 1² + 2(1) - 5 = 1 + 2 -5 = -2
e. f(a+ 2) = 5(a+2) - 2 = 5a + 10 - 2 = 5a + 8
f. g(a + 2) = (a + 2)² + 2(a + 2) - 5 = a² + 4a + 4 + 2a + 4 - 5 =
a² + 6a + 3
Answer:
9.9
Step-by-step explanation:
19 - 9 = 10
10.8 - 0.9
9.9
Answer:
17
Step-by-step explanation:
substitute t = - 9 into f(t) , that is
f(- 9) = - 2(- 9) - 1 = 18 - 1 = 17
