Question 820962
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x + y = V/10
x = V/T
y = V/(T + 15)
V/T + V/(T + 15) = V/10
1/T + 1/(T + 15) = 1/10
(T + 15)/T(T + 15) + T/T(T + 15) = 1/10
T + 15 + T = T(T + 15)/10
(1/10)TT + (15/10)T - 2T - 15 = 0
(1/10)TT + (15/10)T - (20/10)T - 15 = 0
(1/10)TT - (1/2)T - 15 = 0
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the above quadratic equation is in standard form, with a=0.1, b=-0.5, and c=-15
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to solve the quadratic equation, by using the quadratic formula, copy and paste this:
0.1 -0.5 -15
into this solver: https://sooeet.com/math/quadratic-equation-solver.php
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the two real roots (i.e. the two x-intercepts), of the quadratic are:
T = 15
T = -15
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negative time doesn't make sense, so use the positive root
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answer:
first pipe fills tank in 15 hours
second pipe fills tank in 30 hours
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Solve and graph linear equations:
https://sooeet.com/math/linear-equation-solver.php
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Solve quadratic equations, quadratic formula:
https://sooeet.com/math/quadratic-formula-solver.php
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Solve systems of linear equations up to 6-equations 6-variables:
https://sooeet.com/math/system-of-linear-equations-solver.php