Respuesta :
Answer:
1. x= -2
2. x = 1/2 = 0.500
Step-by-step explanation:
Changes made to your input should not affect the solution:
(1): "x2" was replaced by "x^2".
Rearrange:
Rearrange the equation by subtracting what is to the right of the equal sign from both sides of the equation :
2*x^2+3*x-(2)=0
Step by step solution :
Step 1 :
Equation at the end of step 1 :
(2x2 + 3x) - 2 = 0
Step 2 :
Trying to factor by splitting the middle term
2.1 Factoring 2x2+3x-2
The first term is, 2x2 its coefficient is 2 .
The middle term is, +3x its coefficient is 3 .
The last term, "the constant", is -2
Step-1 : Multiply the coefficient of the first term by the constant 2 • -2 = -4
Step-2 : Find two factors of -4 whose sum equals the coefficient of the middle term, which is 3 .
-4 + 1 = -3
-2 + 2 = 0
-1 + 4 = 3 That's it
Step-3 : Rewrite the polynomial splitting the middle term using the two factors found in step 2 above, -1 and 4
2x2 - 1x + 4x - 2
Step-4 : Add up the first 2 terms, pulling out like factors :
x • (2x-1)
Add up the last 2 terms, pulling out common factors :
2 • (2x-1)
Step-5 : Add up the four terms of step 4 :
(x+2) • (2x-1)
Which is the desired factorization
Equation at the end of step 2 :
(2x - 1) • (x + 2) = 0
Step 3 :
Theory - Roots of a product :
3.1 A product of several terms equals zero.
When a product of two or more terms equals zero, then at least one of the terms must be zero.
We shall now solve each term = 0 separately
In other words, we are going to solve as many equations as there are terms in the product
Any solution of term = 0 solves product = 0 as well.
Solving a Single Variable Equation :
3.2 Solve : 2x-1 = 0
Add 1 to both sides of the equation :
2x = 1
Divide both sides of the equation by 2:
x = 1/2 = 0.500
Solving a Single Variable Equation :
3.3 Solve : x+2 = 0
Subtract 2 from both sides of the equation :
x = -2
Supplement : Solving Quadratic Equation Directly
Solving 2x2+3x-2 = 0 directly
Earlier we factored this polynomial by splitting the middle term. let us now solve the equation by Completing The Square and by using the Quadratic Formula
Parabola, Finding the Vertex :
4.1 Find the Vertex of y = 2x2+3x-2
Parabolas have a highest or a lowest point called the Vertex . Our parabola opens up and accordingly has a lowest point (AKA absolute minimum) . We know this even before plotting "y" because the coefficient of the first term, 2 , is positive (greater than zero).
For any parabola,Ax2+Bx+C,the x -coordinate of the vertex is given by -B/(2A) . In our case the x coordinate is -0.7500
Plugging into the parabola formula -0.7500 for x we can calculate the y -coordinate :
y = 2.0 * -0.75 * -0.75 + 3.0 * -0.75 - 2.0
or y = -3.125
Parabola, Graphing Vertex and X-Intercepts :
Root plot for : y = 2x2+3x-2
Axis of Symmetry (dashed) {x}={-0.75}
Vertex at {x,y} = {-0.75,-3.13}
x -Intercepts (Roots) :
Root 1 at {x,y} = {-2.00, 0.00}
Root 2 at {x,y} = { 0.50, 0.00}
Solve Quadratic Equation by Completing The Square
4.2 Solving 2x2+3x-2 = 0 by Completing The Square .
Divide both sides of the equation by 2 to have 1 as the coefficient of the first term :
x2+(3/2)x-1 = 0
Add 1 to both side of the equation :
x2+(3/2)x = 1
Now the clever bit: Take the coefficient of x , which is 3/2 , divide by two, giving 3/4 , and finally square it giving 9/16
Add 9/16 to both sides of the equation :
On the right hand side we have :
1 + 9/16 or, (1/1)+(9/16)
The common denominator of the two fractions is 16 Adding (16/16)+(9/16) gives 25/16
So adding to both sides we finally get :
x2+(3/2)x+(9/16) = 25/16
Note that the square root of
(x+(3/4))2 is
(x+(3/4))2/2 =
(x+(3/4))1 =
x+(3/4)
Now, applying the Square Root Principle to Eq. #4.2.1 we get:
x+(3/4) = √ 25/16
Subtract 3/4 from both sides to obtain:
x = -3/4 + √ 25/16
Since a square root has two values, one positive and the other negative
x2 + (3/2)x - 1 = 0
has two solutions:
x = -3/4 + √ 25/16
or
x = -3/4 - √ 25/16
Note that √ 25/16 can be written as
√ 25 / √ 16 which is 5 / 4
Solve Quadratic Equation using the Quadratic Formula
4.3 Solving 2x2+3x-2 = 0 by the Quadratic Formula .
According to the Quadratic Formula, x , the solution for Ax2+Bx+C = 0 , where A, B and C are numbers, often called coefficients, is given by :
- B ± √ B2-4AC
x = ————————
2A
In our case, A = 2
B = 3
C = -2
Accordingly, B2 - 4AC =
9 - (-16) =
25
Applying the quadratic formula :
-3 ± √ 25
x = —————
4
Can √ 25 be simplified ?
Yes! The prime factorization of 25 is
5•5
To be able to remove something from under the radical, there have to be 2 instances of it (because we are taking a square i.e. second root).
√ 25 = √ 5•5 =
± 5 • √ 1 =
± 5
So now we are looking at:
x = ( -3 ± 5) / 4
Two real solutions:
x =(-3+√25)/4=(-3+5)/4= 0.500
or:
x =(-3-√25)/4=(-3-5)/4= -2.000
Answer:
[tex]x = \frac{1}{2}[/tex] or [tex]x = -2[/tex]
Step-by-step explanation:
[tex]2x^{2} + 3x = 2[/tex]
[tex]2x^{2} +3x-2=0\\\\(2x-1)(x+2)=0\\\\2x-1=0\\\\[/tex]
[tex]x=\frac{1}{2} \\\\x+2=0\\\\x=-2[/tex]
