Solve for x
x=5
x=10
Graph
Quiz
Quadratic Equation
5 problems similar to:
1 - \frac { 15 } { x } + \frac { 50 } { x ^ { 2 } } = 0
Share
Copied to clipboard
x^{2}-x\times 15+50=0
Variable x cannot be equal to 0 since division by zero is not defined. Multiply both sides of the equation by x^{2}, the least common multiple of x,x^{2}.
x^{2}-15x+50=0
Multiply -1 and 15 to get -15.
a+b=-15 ab=50
To solve the equation, factor x^{2}-15x+50 using formula x^{2}+\left(a+b\right)x+ab=\left(x+a\right)\left(x+b\right). To find a and b, set up a system to be solved.
-1,-50 -2,-25 -5,-10
Since ab is positive, a and b have the same sign. Since a+b is negative, a and b are both negative. List all such integer pairs that give product 50.
-1-50=-51 -2-25=-27 -5-10=-15
Calculate the sum for each pair.
a=-10 b=-5
The solution is the pair that gives sum -15.
\left(x-10\right)\left(x-5\right)
Rewrite factored expression \left(x+a\right)\left(x+b\right) using the obtained values.
x=10 x=5
To find equation solutions, solve x-10=0 and x-5=0.
x^{2}-x\times 15+50=0
Variable x cannot be equal to 0 since division by zero is not defined. Multiply both sides of the equation by x^{2}, the least common multiple of x,x^{2}.
x^{2}-15x+50=0
Multiply -1 and 15 to get -15.
a+b=-15 ab=1\times 50=50
To solve the equation, factor the left hand side by grouping. First, left hand side needs to be rewritten as x^{2}+ax+bx+50. To find a and b, set up a system to be solved.
-1,-50 -2,-25 -5,-10
Since ab is positive, a and b have the same sign. Since a+b is negative, a and b are both negative. List all such integer pairs that give product 50.
-1-50=-51 -2-25=-27 -5-10=-15
Calculate the sum for each pair.
a=-10 b=-5
The solution is the pair that gives sum -15.
\left(x^{2}-10x\right)+\left(-5x+50\right)
Rewrite x^{2}-15x+50 as \left(x^{2}-10x\right)+\left(-5x+50\right).
x\left(x-10\right)-5\left(x-10\right)
Factor out x in the first and -5 in the second group.
\left(x-10\right)\left(x-5\right)
Factor out common term x-10 by using distributive property.
x=10 x=5
To find equation solutions, solve x-10=0 and x-5=0.
x^{2}-x\times 15+50=0
Variable x cannot be equal to 0 since division by zero is not defined. Multiply both sides of the equation by x^{2}, the least common multiple of x,x^{2}.
x^{2}-15x+50=0
Multiply -1 and 15 to get -15.
x=\frac{-\left(-15\right)±\sqrt{\left(-15\right)^{2}-4\times 50}}{2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, -15 for b, and 50 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-15\right)±\sqrt{225-4\times 50}}{2}
Square -15.
x=\frac{-\left(-15\right)±\sqrt{225-200}}{2}
Multiply -4 times 50.
x=\frac{-\left(-15\right)±\sqrt{25}}{2}
Add 225 to -200.
x=\frac{-\left(-15\right)±5}{2}
Take the square root of 25.
x=\frac{15±5}{2}
The opposite of -15 is 15.
x=\frac{20}{2}
Now solve the equation x=\frac{15±5}{2} when ± is plus. Add 15 to 5.
x=10
Divide 20 by 2.
x=\frac{10}{2}
Now solve the equation x=\frac{15±5}{2} when ± is minus. Subtract 5 from 15.
x=5
Divide 10 by 2.
x=10 x=5
The equation is now solved.
x^{2}-x\times 15+50=0
Variable x cannot be equal to 0 since division by zero is not defined. Multiply both sides of the equation by x^{2}, the least common multiple of x,x^{2}.
x^{2}-x\times 15=-50
Subtract 50 from both sides. Anything subtracted from zero gives its negation.
x^{2}-15x=-50
Multiply -1 and 15 to get -15.
x^{2}-15x+\left(-\frac{15}{2}\right)^{2}=-50+\left(-\frac{15}{2}\right)^{2}
Divide -15, the coefficient of the x term, by 2 to get -\frac{15}{2}. Then add the square of -\frac{15}{2} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-15x+\frac{225}{4}=-50+\frac{225}{4}
Square -\frac{15}{2} by squaring both the numerator and the denominator of the fraction.
x^{2}-15x+\frac{225}{4}=\frac{25}{4}
Add -50 to \frac{225}{4}.
\left(x-\frac{15}{2}\right)^{2}=\frac{25}{4}
Factor x^{2}-15x+\frac{225}{4}. 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(x-\frac{15}{2}\right)^{2}}=\sqrt{\frac{25}{4}}
Take the square root of both sides of the equation.
x-\frac{15}{2}=\frac{5}{2} x-\frac{15}{2}=-\frac{5}{2}
Simplify.
x=10 x=5
Add \frac{15}{2} to both sides of the equation.
Examples
Quadratic equation
{ x } ^ { 2 } - 4 x - 5 = 0
Trigonometry
4 \sin \theta \cos \theta = 2 \sin \theta
Linear equation
y = 3x + 4
Arithmetic
699 * 533
Matrix
\left[ \begin{array} { l l } { 2 } & { 3 } \\ { 5 } & { 4 } \end{array} \right] \left[ \begin{array} { l l l } { 2 } & { 0 } & { 3 } \\ { -1 } & { 1 } & { 5 } \end{array} \right]
Simultaneous equation
\left. \begin{cases} { 8x+2y = 46 } \\ { 7x+3y = 47 } \end{cases} \right.
Differentiation
\frac { d } { d x } \frac { ( 3 x ^ { 2 } - 2 ) } { ( x - 5 ) }
Integration
\int _ { 0 } ^ { 1 } x e ^ { - x ^ { 2 } } d x
Limits
\lim _{x \rightarrow-3} \frac{x^{2}-9}{x^{2}+2 x-3}