Mister Exam
Other calculators
-
How to use it?
- Equation:
-
Equation -x/12+x=55/12
-
Equation x^2-2x+5=0
-
Equation cos(x)=2/3
-
Equation 4x+1=-3x+15
- Express {x} in terms of y where:
- -4*x+6*y=-7
- 2*x+3*y=14
- 18*x-8*y=-2
- 10*x-16*y=-6
-
Identical expressions
- (x+ three)*(x+ four)= zero
- (x plus 3) multiply by (x plus 4) equally 0
- (x plus three) multiply by (x plus four) equally zero
- (x+3)(x+4)=0
- x+3x+4=0
- (x+3)*(x+4)=O
-
Similar expressions
- (x+3)*(x-4)=0
- x(x+1)(x+2)(x+3)(x+4)=2016
- (x*x+3x+2)*(x*x+3x+4)
- (x(x+3)(x+4))/x^2-4x=0
- (x-3)*(x+4)=0
(x+3)*(x+4)=0 equation
The teacher will be very surprised to see your correct solution 😉
The solution
Detail solution
Expand the expression in the equation
$$\left(x + 3\right) \left(x + 4\right) + 0 = 0$$
We get the quadratic equation
$$x^{2} + 7 x + 12 = 0$$
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
$$a = 1$$
$$b = 7$$
$$c = 12$$
, then
Because D > 0, then the equation has two roots.
or
$$x_{1} = -3$$
Simplify
$$x_{2} = -4$$
Simplify
$$\left(x + 3\right) \left(x + 4\right) + 0 = 0$$
We get the quadratic equation
$$x^{2} + 7 x + 12 = 0$$
This equation is of the form
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
$$a = 1$$
$$b = 7$$
$$c = 12$$
, then
D = b^2 - 4 * a * c =
(7)^2 - 4 * (1) * (12) = 1
Because D > 0, then the equation has two roots.
x1 = (-b + sqrt(D)) / (2*a)
x2 = (-b - sqrt(D)) / (2*a)
or
$$x_{1} = -3$$
Simplify
$$x_{2} = -4$$
Simplify
Sum and product of roots
[src]
sum
0 - 4 - 3
$$\left(-4 + 0\right) - 3$$
=
-7
$$-7$$
product
1*-4*-3
$$1 \left(-4\right) \left(-3\right)$$
=
12
$$12$$
12
The graph