6 x + 5 \cdot 1 = - 4 \cdot 5 - 5 ( \sqrt { x + 4 } + 5
Solve for x (complex solution)
x=\frac{-5\sqrt{599}i-575}{72}\approx -7.986111111-1.699616424i
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6x+5=-4\times 5-5\left(\sqrt{x+4}+5\right)
Multiply 5 and 1 to get 5.
6x+5=-20-5\left(\sqrt{x+4}+5\right)
Multiply -4 and 5 to get -20.
6x+5+5\left(\sqrt{x+4}+5\right)=-20
Add 5\left(\sqrt{x+4}+5\right) to both sides.
6x+5+5\sqrt{x+4}+25=-20
Use the distributive property to multiply 5 by \sqrt{x+4}+5.
6x+30+5\sqrt{x+4}=-20
Add 5 and 25 to get 30.
6x+5\sqrt{x+4}=-20-30
Subtract 30 from both sides.
6x+5\sqrt{x+4}=-50
Subtract 30 from -20 to get -50.
5\sqrt{x+4}=-50-6x
Subtract 6x from both sides of the equation.
\left(5\sqrt{x+4}\right)^{2}=\left(-50-6x\right)^{2}
Square both sides of the equation.
5^{2}\left(\sqrt{x+4}\right)^{2}=\left(-50-6x\right)^{2}
Expand \left(5\sqrt{x+4}\right)^{2}.
25\left(\sqrt{x+4}\right)^{2}=\left(-50-6x\right)^{2}
Calculate 5 to the power of 2 and get 25.
25\left(x+4\right)=\left(-50-6x\right)^{2}
Calculate \sqrt{x+4} to the power of 2 and get x+4.
25x+100=\left(-50-6x\right)^{2}
Use the distributive property to multiply 25 by x+4.
25x+100=2500+600x+36x^{2}
Use binomial theorem \left(a-b\right)^{2}=a^{2}-2ab+b^{2} to expand \left(-50-6x\right)^{2}.
25x+100-600x=2500+36x^{2}
Subtract 600x from both sides.
-575x+100=2500+36x^{2}
Combine 25x and -600x to get -575x.
-575x+100-36x^{2}=2500
Subtract 36x^{2} from both sides.
-36x^{2}-575x+100=2500
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.
-36x^{2}-575x+100-2500=2500-2500
Subtract 2500 from both sides of the equation.
-36x^{2}-575x+100-2500=0
Subtracting 2500 from itself leaves 0.
-36x^{2}-575x-2400=0
Subtract 2500 from 100.
x=\frac{-\left(-575\right)±\sqrt{\left(-575\right)^{2}-4\left(-36\right)\left(-2400\right)}}{2\left(-36\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -36 for a, -575 for b, and -2400 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-575\right)±\sqrt{330625-4\left(-36\right)\left(-2400\right)}}{2\left(-36\right)}
Square -575.
x=\frac{-\left(-575\right)±\sqrt{330625+144\left(-2400\right)}}{2\left(-36\right)}
Multiply -4 times -36.
x=\frac{-\left(-575\right)±\sqrt{330625-345600}}{2\left(-36\right)}
Multiply 144 times -2400.
x=\frac{-\left(-575\right)±\sqrt{-14975}}{2\left(-36\right)}
Add 330625 to -345600.
x=\frac{-\left(-575\right)±5\sqrt{599}i}{2\left(-36\right)}
Take the square root of -14975.
x=\frac{575±5\sqrt{599}i}{2\left(-36\right)}
The opposite of -575 is 575.
x=\frac{575±5\sqrt{599}i}{-72}
Multiply 2 times -36.
x=\frac{575+5\sqrt{599}i}{-72}
Now solve the equation x=\frac{575±5\sqrt{599}i}{-72} when ± is plus. Add 575 to 5i\sqrt{599}.
x=\frac{-5\sqrt{599}i-575}{72}
Divide 575+5i\sqrt{599} by -72.
x=\frac{-5\sqrt{599}i+575}{-72}
Now solve the equation x=\frac{575±5\sqrt{599}i}{-72} when ± is minus. Subtract 5i\sqrt{599} from 575.
x=\frac{-575+5\sqrt{599}i}{72}
Divide 575-5i\sqrt{599} by -72.
x=\frac{-5\sqrt{599}i-575}{72} x=\frac{-575+5\sqrt{599}i}{72}
The equation is now solved.
6\times \frac{-5\sqrt{599}i-575}{72}+5\times 1=-4\times 5-5\left(\sqrt{\frac{-5\sqrt{599}i-575}{72}+4}+5\right)
Substitute \frac{-5\sqrt{599}i-575}{72} for x in the equation 6x+5\times 1=-4\times 5-5\left(\sqrt{x+4}+5\right).
-\frac{5}{12}i\times 599^{\frac{1}{2}}-\frac{515}{12}=-\frac{515}{12}-\frac{5}{12}i\times 599^{\frac{1}{2}}
Simplify. The value x=\frac{-5\sqrt{599}i-575}{72} satisfies the equation.
6\times \frac{-575+5\sqrt{599}i}{72}+5\times 1=-4\times 5-5\left(\sqrt{\frac{-575+5\sqrt{599}i}{72}+4}+5\right)
Substitute \frac{-575+5\sqrt{599}i}{72} for x in the equation 6x+5\times 1=-4\times 5-5\left(\sqrt{x+4}+5\right).
-\frac{515}{12}+\frac{5}{12}i\times 599^{\frac{1}{2}}=-\frac{565}{12}-\frac{5}{12}i\times 599^{\frac{1}{2}}
Simplify. The value x=\frac{-575+5\sqrt{599}i}{72} does not satisfy the equation.
x=\frac{-5\sqrt{599}i-575}{72}
Equation 5\sqrt{x+4}=-6x-50 has a unique solution.
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