How to do middle term splitting
Answers
Answer:
Step-by-step explanation:
In a quadratic equation, where you will have three terms : x² , x, coefficient. We will split the middle term to two terms, so that we can factorize the quadratic equation and find root.
So, Let's first know what is a Quadratic equation?
A quadratic equation is a polynomial of degree 2 , So the term with greatest degree would have a degree of 2 .
So , Basically, Quadratic equation can have 2 roots and in cases there might be 1 too.
Now, What's the general form of a quadratic equation?
The general form of a quadratic equation is ax² + bx + c.
So, Let us consider that β , α are the roots.
Thus x = α , β then ( x - α ) ( x - β ) is the quadratic polynomial.
Simplifying it as following ,
x ( x - β ) - α ( x - β )
x² - (α+ β)x + αβ
So , Comparing this with general equation.
ax² + bx + c = x² - (α + β)x + αβ
x² + b/a x + c/a = x² - (α+β)x + αβ
Comparing,
b/a = - (α + β)
c/a = αβ
So , If we are given a quadratic equation of dx² + ex + f, Middle term is mostly used when d = 1 , that is when you have to find
.roots having a product of f and having a sum of negative e.
As you have asked for a example let's see an example.
x² - 33x + 200
Here ,The numbers might seem large and basically you might be taking it hard to solve. but Basically it's just easy.
So, Here coefficient of x = 1 .
We should look for numbers whose product equals 200 .
So the pairs that do come into mind are 1 * 200 , 2 * 100 , 4 * 50 , 5 * 40 , 10 * 20 , 25 * 8 .
So, The next condition is the sum of numbers we choose must be negative the coefficient of x.
Here, Coefficient of x = -33
Negative of coefficient of x = 33 .
So , From the above pairs ( 25 , 8 ) have a sum of 33 .
Now, The big quadratic equation which seemed too tough looks like this
x² - ( 25 + 8 ) x + (25*8)
Which is looking very easily to solve, Let's factorise :)
x² -25x - 8x + 300
x ( x - 25 ) -8 ( x - 25)
( x - 25 ) ( x - 8 )
So, the above are the factors.
if you want zeroes, Just equate them with zero
x - 25 = 0 , x = 25
x - 8 = 0 , x = 0 .
So, We must look for the factor pairs of the coefficient of constant, so that problem is easy.
There are quadratic equations like 3x² + 6x - 9 where Coefficient of x² isn't 1 , in that case, divide the entire polynomial by coefficient of x² and after factorising multiply one of the factor by the coefficient of x²
The above polynomial becomes x² + 2x - 3
x² + 2x - 3
= x² + 3x - x - 3
= x ( x + 3 ) -1 ( x - 3 )
= ( x - 1 )( x - 3)
Multiply any of factor by 3 .
= (3x - 3 ) ( x - 3 )
= ( x - 1 ) ( 3x - 9 )
Which ever the factor, you multiply won't change the roots. So no worries in that.
Step-by-step explanation:
let the equation is 2x²+ 6x-20=0 { ax²+bx-c=o}
- then just multiply the coefficient of x² and c : 2*20=40 .
- now factorise 40 you got 2*2*2*5.
- now find two number (from the numbers you obtained by factorising) whose subtraction is 6 and multiplication is 40 ( as here is 6x-20 if here 6x+20 then you will have two find whose sum is 6).
- hence two numbers are 10 and 4. putting it in the place of 6x . we get: 2x²+(10-4)x-20=0 2x²+10x-4x-20=0
- now taking common we got : 2x(X+5) -4(x-5)=0 . {the digits under brackets must have to be same }
- now simply write : (x-5) (2x-4)
- hence solution is X+5=0
X=-5
- 2x-4=0
X=4/2
X=2
its too much lengthy but hope that you will understand!!