Mister Exam
Other calculators
-
How to use it?
- Equation:
-
Equation (x+2)^2=(x-8)^2
-
Equation -x=3
-
Equation x^2+6*x+9=0
-
Equation 12/(x+3)=-6/7
- Express {x} in terms of y where:
- -4*x+19*y=-13
- -5*x-6*y=-1
- -16*x-2*y=4
- -7*x+15*y=18
-
Identical expressions
- x^ two + two *x- eighty = zero
- x squared plus 2 multiply by x minus 80 equally 0
- x to the power of two plus two multiply by x minus eighty equally zero
- x2+2*x-80=0
- x²+2*x-80=0
- x to the power of 2+2*x-80=0
- x^2+2x-80=0
- x2+2x-80=0
- x^2+2*x-80=O
-
Similar expressions
- x^2+2*x+80=0
- x^2-2*x-80=0
x^2+2*x-80=0 equation
The teacher will be very surprised to see your correct solution 😉
The solution
Detail solution
This equation is of the form
A quadratic equation can be solved
using the discriminant.
The roots of the quadratic equation:
$$x_{1} = \frac{\sqrt{D} - b}{2 a}$$
$$x_{2} = \frac{- \sqrt{D} - b}{2 a}$$
where D = b^2 - 4*a*c - it is the discriminant.
Because
$$a = 1$$
$$b = 2$$
$$c = -80$$
, then
Because D > 0, then the equation has two roots.
or
$$x_{1} = 8$$
$$x_{2} = -10$$
a*x^2 + b*x + c = 0
A quadratic equation can be solved
using the discriminant.
The roots of the quadratic equation:
$$x_{1} = \frac{\sqrt{D} - b}{2 a}$$
$$x_{2} = \frac{- \sqrt{D} - b}{2 a}$$
where D = b^2 - 4*a*c - it is the discriminant.
Because
$$a = 1$$
$$b = 2$$
$$c = -80$$
, then
D = b^2 - 4 * a * c =
(2)^2 - 4 * (1) * (-80) = 324
Because D > 0, then the equation has two roots.
x1 = (-b + sqrt(D)) / (2*a)
x2 = (-b - sqrt(D)) / (2*a)
or
$$x_{1} = 8$$
$$x_{2} = -10$$
Vieta's Theorem
it is reduced quadratic equation
$$p x + q + x^{2} = 0$$
where
$$p = \frac{b}{a}$$
$$p = 2$$
$$q = \frac{c}{a}$$
$$q = -80$$
Vieta Formulas
$$x_{1} + x_{2} = - p$$
$$x_{1} x_{2} = q$$
$$x_{1} + x_{2} = -2$$
$$x_{1} x_{2} = -80$$
$$p x + q + x^{2} = 0$$
where
$$p = \frac{b}{a}$$
$$p = 2$$
$$q = \frac{c}{a}$$
$$q = -80$$
Vieta Formulas
$$x_{1} + x_{2} = - p$$
$$x_{1} x_{2} = q$$
$$x_{1} + x_{2} = -2$$
$$x_{1} x_{2} = -80$$
Sum and product of roots
[src]
sum
-10 + 8
$$-10 + 8$$
=
-2
$$-2$$
product
-10*8
$$- 80$$
=
-80
$$-80$$
-80