Anyone please answer this question with full step by step explanation by using factorisation method. Anyone please answer this question with full step by step explanation. Don't post irrelevant answers. Anyone please answer this question with full step by step explanation.
Answers
Answer:
Step-by-step explanation:
1) x²-2x-15
x²-5x+3x-15
x(x-5)+3(x-5)
(x-5)(x+3)
x = 5, -3
2) 12x²-13x-4
12x²-16x+3x-4
4x(3x-4)+1(3x-4)
(3x-4)(4x+1)
x = 4/3 , -1/4
3) 6x²+13x+6
6x²+9x+4x+6
3x(2x+3)+2(2x+3)
(2x+3)(3x+2)
x = -3/2 , -2/3
4) x²+7x+12
x²+4x+3x+12
x(x+4)+3(x+4)
(x+4)(x+3)
x = -4 , -3
5) 2x²-5x-3
2x²-6x+x-3
2x(x-3)+1(x-3)
(x-3)(2x+1)
x = 3, -1/2
done... ;)
My answer is going to be a little longer but I will try me best to make you understand this concept of Factorisation.
1) Split the middle term i.e coefficient of x.
Split Middle term, How ?
2) Multiply the coefficient of x² with constant (a) You will surely get a no.
Now, Split the middle term as product of x²a is equal to product of splited middle terms coefficient and their sum is vice versa.
e.g x² - 2x - 15
Coefficient of x² = 1
Constant = 15
So, Product = 1(15) = 15
Now, We have to follow rule 1
-2x can be written as = 5x - 3x , We can see 5 × 3 = 15
Now, Solving the question,
x² - 2x - 15
= x²-(5x-3x)-15
= x² -5x + 3x -15
=x(x-5) + 3(x-5)
=(x+3)(x-5)
Take another example,
e.g 6x² +13x +6
Coefficient of x² = 6
Constant = 6
So, Product = 6(6) = 36
Now, We have to follow rule 1
13x can be written as = 9x +4x , We can see 4 × 9 = 15
Now, Solving the question,
x²+13x+6
= 6x²+(9x+4x)+6
= 6x²+9x +4x +6
=3x(2x+3) +3(2x+3)
=(2x+3)(3x+3)
