Is -0.4 a rational number?
1 answer:
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Answer:
Step-by-step explanation:
<u><em>Given Equation is </em></u>
=>
Comparing it with , we get
=> a = 2, b = 7 and c = -9
So,
Sum of roots = α+β =
α+β = -7/2
Product of roots = αβ = c/a
αβ = -9/2
<em>Now, Finding the equation whose roots are:</em>
α/β ,β/α
Sum of Roots =
Sum of Roots =
Sum of Roots =
Sum of roots =
Sum of roots =
Sum of Roots =
Sum of roots =
Sum of roots = S =
Product of Roots =
Product of Roots = P = 1
<u><em>The Quadratic Equation is:</em></u>
=>
=>
=>
=>
This is the required quadratic equation.
Answer:
Speed of Current = 5 miles per hour
Step-by-step explanation:
We know distance formula,
D = RT
Where
D is distance
R is rate
T is time
If we let speed of boat (assume) to be "x" and speed of current to be "c"
Then downstream rate is (with current) = x + c
Upstream rate is (against current) = x - c
40 mins to go 20 miles downstream, that means:
D = RT
20 = (x + c)(40)
and
60 minutes to go upstream, 20 miles, that means:
D = RT
20 = (x - c)(60)
Simplifying first equation:
40x + 40c = 20
Simplifying second equation:
60x - 60c = 20
Multiplying first equation by 60, we get:
60 * [40x + 40c = 20] = 2400x + 2400c = 1200
Multiplying second equation by 40, we get:
40 * [60x - 60c = 20] = 2400x - 2400c = 800
Now we add up both these equations:
2400x + 2400c = 1200
2400x - 2400c = 800
----------------------------------
4800x = 2000
x = 2000/4800 = 5/12
We need speed of current, that is "c", so we plug in the value of x into first equation and solve for c:
Speed of Current = 1/12 miles per minute
Since there is 60 minutes in an hours, that would be:
(1/12) * 60 = 5 miles per hour
Speed of Current = 5 miles per hour