Solve for t
t=-10
t=12
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0=5tt-600+t\left(-10\right)
Variable t cannot be equal to 0 since division by zero is not defined. Multiply both sides of the equation by t.
0=5t^{2}-600+t\left(-10\right)
Multiply t and t to get t^{2}.
5t^{2}-600+t\left(-10\right)=0
Swap sides so that all variable terms are on the left hand side.
t^{2}-120-2t=0
Divide both sides by 5.
t^{2}-2t-120=0
Rearrange the polynomial to put it in standard form. Place the terms in order from highest to lowest power.
a+b=-2 ab=1\left(-120\right)=-120
To solve the equation, factor the left hand side by grouping. First, left hand side needs to be rewritten as t^{2}+at+bt-120. To find a and b, set up a system to be solved.
1,-120 2,-60 3,-40 4,-30 5,-24 6,-20 8,-15 10,-12
Since ab is negative, a and b have the opposite signs. Since a+b is negative, the negative number has greater absolute value than the positive. List all such integer pairs that give product -120.
1-120=-119 2-60=-58 3-40=-37 4-30=-26 5-24=-19 6-20=-14 8-15=-7 10-12=-2
Calculate the sum for each pair.
a=-12 b=10
The solution is the pair that gives sum -2.
\left(t^{2}-12t\right)+\left(10t-120\right)
Rewrite t^{2}-2t-120 as \left(t^{2}-12t\right)+\left(10t-120\right).
t\left(t-12\right)+10\left(t-12\right)
Factor out t in the first and 10 in the second group.
\left(t-12\right)\left(t+10\right)
Factor out common term t-12 by using distributive property.
t=12 t=-10
To find equation solutions, solve t-12=0 and t+10=0.
0=5tt-600+t\left(-10\right)
Variable t cannot be equal to 0 since division by zero is not defined. Multiply both sides of the equation by t.
0=5t^{2}-600+t\left(-10\right)
Multiply t and t to get t^{2}.
5t^{2}-600+t\left(-10\right)=0
Swap sides so that all variable terms are on the left hand side.
5t^{2}-10t-600=0
All equations of the form ax^{2}+bx+c=0 can be solved using the quadratic formula: \frac{-b±\sqrt{b^{2}-4ac}}{2a}. The quadratic formula gives two solutions, one when ± is addition and one when it is subtraction.
t=\frac{-\left(-10\right)±\sqrt{\left(-10\right)^{2}-4\times 5\left(-600\right)}}{2\times 5}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 5 for a, -10 for b, and -600 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
t=\frac{-\left(-10\right)±\sqrt{100-4\times 5\left(-600\right)}}{2\times 5}
Square -10.
t=\frac{-\left(-10\right)±\sqrt{100-20\left(-600\right)}}{2\times 5}
Multiply -4 times 5.
t=\frac{-\left(-10\right)±\sqrt{100+12000}}{2\times 5}
Multiply -20 times -600.
t=\frac{-\left(-10\right)±\sqrt{12100}}{2\times 5}
Add 100 to 12000.
t=\frac{-\left(-10\right)±110}{2\times 5}
Take the square root of 12100.
t=\frac{10±110}{2\times 5}
The opposite of -10 is 10.
t=\frac{10±110}{10}
Multiply 2 times 5.
t=\frac{120}{10}
Now solve the equation t=\frac{10±110}{10} when ± is plus. Add 10 to 110.
t=12
Divide 120 by 10.
t=-\frac{100}{10}
Now solve the equation t=\frac{10±110}{10} when ± is minus. Subtract 110 from 10.
t=-10
Divide -100 by 10.
t=12 t=-10
The equation is now solved.
0=5tt-600+t\left(-10\right)
Variable t cannot be equal to 0 since division by zero is not defined. Multiply both sides of the equation by t.
0=5t^{2}-600+t\left(-10\right)
Multiply t and t to get t^{2}.
5t^{2}-600+t\left(-10\right)=0
Swap sides so that all variable terms are on the left hand side.
5t^{2}+t\left(-10\right)=600
Add 600 to both sides. Anything plus zero gives itself.
5t^{2}-10t=600
Quadratic equations such as this one can be solved by completing the square. In order to complete the square, the equation must first be in the form x^{2}+bx=c.
\frac{5t^{2}-10t}{5}=\frac{600}{5}
Divide both sides by 5.
t^{2}+\left(-\frac{10}{5}\right)t=\frac{600}{5}
Dividing by 5 undoes the multiplication by 5.
t^{2}-2t=\frac{600}{5}
Divide -10 by 5.
t^{2}-2t=120
Divide 600 by 5.
t^{2}-2t+1=120+1
Divide -2, the coefficient of the x term, by 2 to get -1. Then add the square of -1 to both sides of the equation. This step makes the left hand side of the equation a perfect square.
t^{2}-2t+1=121
Add 120 to 1.
\left(t-1\right)^{2}=121
Factor t^{2}-2t+1. In general, when x^{2}+bx+c is a perfect square, it can always be factored as \left(x+\frac{b}{2}\right)^{2}.
\sqrt{\left(t-1\right)^{2}}=\sqrt{121}
Take the square root of both sides of the equation.
t-1=11 t-1=-11
Simplify.
t=12 t=-10
Add 1 to both sides of the equation.
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