Jack and Jills' speed in miles per hour is 4
The given parameters are:
Jack speed = x^2-11x-22
Jill distance = x^2-3x-54 and time = x + 6
Speed is calculated as:
Speed = Distance/time
So, we have:
Jill speed = x^2-3x-54/x + 6
Factorize the numerator
Jill speed = (x + 6)(x - 9)/x + 6
Cancel the common factor
Jill speed = x - 9
Both speeds are equal.
So, we have:
x^2-11x-22 = x - 9
Collect like terms
x^2-11x - x -22 + 9 = 0
Evaluate
x^2 - 12x - 13 = 0
Factorize the expression
(x + 1)(x - 13) = 0
Solve for x
x = -1 or x = 13
x cannot be negative.
So, we have:
x =13
Substitute x =13 in Jill speed = x - 9
Jill speed = 13 - 9
Evaluate
Jill speed = 4
Hence, their speed in miles per hour is 4
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