x^2-26x-291 do it in factorisation method
Answers
Step-by-step explanation:
1.1 Factoring x2-26x+168
The first term is, x2 its coefficient is 1 .
The middle term is, -26x its coefficient is -26 .
The last term, "the constant", is +168
Step-1 : Multiply the coefficient of the first term by the constant 1 • 168 = 168
Step-2 : Find two factors of 168 whose sum equals the coefficient of the middle term, which is -26 .
-168 + -1 = -169
-84 + -2 = -86
-56 + -3 = -59
-42 + -4 = -46
-28 + -6 = -34
-24 + -7 = -31
-21 + -8 = -29
-14 + -12 = -26 That's it
Step-3 : Rewrite the polynomial splitting the middle term using the two factors found in step 2 above, -14 and -12
x2 - 14x - 12x - 168
Step-4 : Add up the first 2 terms, pulling out like factors :
x • (x-14)
Add up the last 2 terms, pulling out common factors :
12 • (x-14)
Step-5 : Add up the four terms of step 4 :
(x-12) • (x-14)
Which is the desired factorization
Equation at the end of step
1
:
(x - 12) • (x - 14) = 0
STEP
2
:
Theory - Roots of a product
2.1 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:
2.2 Solve : x-12 = 0
Add 12 to both sides of the equation :
x = 12
Solving a Single Variable Equation:
2.3 Solve : x-14 = 0
Add 14 to both sides of the equation :
x = 14
Supplement : Solving Quadratic Equation Directly
Solving x2-26x+168 = 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:
3.1 Find the Vertex of y = x2-26x+168
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, 1 , 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 13.0000
Plugging into the parabola formula 13.0000 for x we can calculate the y -coordinate :
y = 1.0 * 13.00 * 13.00 - 26.0 * 13.00 + 168.0
or y = -1.000
Parabola, Graphing Vertex and X-Intercepts :
Root plot for : y = x2-26x+168
Axis of Symmetry (dashed) {x}={13.00}
Vertex at {x,y} = {13.00,-1.00}
x -Intercepts (Roots) :
Root 1 at {x,y} = {12.00, 0.00}
Root 2 at {x,y} = {14.00, 0.00}