Step-by-step explanation: Reformatting the input :
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 :
p*(x)-((2*x^2-9*x+7)*(x-2))=0
STEP
1
:
Equation at the end of step 1
px - (((2x2 - 9x) + 7) • (x - 2)) = 0
STEP
2
:
Trying to factor by splitting the middle term
2.1 Factoring 2x2-9x+7
The first term is, 2x2 its coefficient is 2 .
The middle term is, -9x its coefficient is -9 .
The last term, "the constant", is +7
Step-1 : Multiply the coefficient of the first term by the constant 2 • 7 = 14
Step-2 : Find two factors of 14 whose sum equals the coefficient of the middle term, which is -9 .
-14 + -1 = -15
-7 + -2 = -9 That's it
Step-3 : Rewrite the polynomial splitting the middle term using the two factors found in step 2 above, -7 and -2
2x2 - 7x - 2x - 7
Step-4 : Add up the first 2 terms, pulling out like factors :
x • (2x-7)
Add up the last 2 terms, pulling out common factors :
1 • (2x-7)
Step-5 : Add up the four terms of step 4 :
(x-1) • (2x-7)
Which is the desired factorization
Equation at the end of step
2
:
px - (2x - 7) • (x - 1) • (x - 2) = 0
STEP
3
:
Equation at the end of step 3
px - 2x3 + 13x2 - 25x + 14 = 0
STEP
4
:
Solving a Single Variable Equation:
4.1 Solve px-2x3+13x2-25x+14 = 0
In this type of equations, having more than one variable (unknown), you have to specify for which variable you want the equation solved.
We shall not handle this type of equations at this time.
Supplement : Solving Quadratic Equation Directly
Solving 2x2-9x+7 = 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:
5.1 Find the Vertex of y = 2x2-9x+7
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).
Each parabola has a vertical line of symmetry that passes through its vertex. Because of this symmetry, the line of symmetry would, for example, pass through the midpoint of the two x -intercepts (roots or solutions) of the parabola. That is, if the parabola has indeed two real solutions.
Parabolas can model many real life situations, such as the height above ground, of an object thrown upward, after some period of time. The vertex of the parabola can provide us with information, such as the maximum height that object, thrown upwards, can reach. For this reason we want to be able to find the coordinates of the vertex.
For any parabola,Ax2+Bx+C,the x -coordinate of the vertex is given by -B/(2A) . In our case the x coordinate is 2.2500
Plugging into the parabola formula 2.2500 for x we can calculate the y -coordinate :
y = 2.0 * 2.25 * 2.25 - 9.0 * 2.25 + 7.0
or y = -3.125
Parabola, Graphing Vertex and X-Intercepts :
Root plot for : y = 2x2-9x+7
Axis of Symmetry (dashed) {x}={ 2.25}
Vertex at {x,y} = { 2.25,-3.12}
x -Intercepts (Roots) :
Root 1 at {x,y} = { 1.00, 0.00}
Root 2 at {x,y} = { 3.50, 0.00}
3 Solving 2x2-9x+7 = 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 = -9
C = 7
Accordingly, B2 - 4AC =
81 - 56 =
25
Applying the quadratic formula :
9 ± √ 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 = ( 9 ± 5) / 4
Two real solutions:
x =(9+√25)/4=(9+5)/4= 3.500
or:
x =(9-√25)/4=(9-5)/4= 1.000
