Factorise: 36y⁴-25y²+4
Answers
Answer:
- Factorised form – (3y - 2)(3y + 2)(2y + 1)(2y - 1).
Solution:
Given To Factorise:
= 36y⁴ - 25y² + 4
We can rewrite it as:
= 36y⁴ - 24y² + 4 - y²
= (36y⁴ - 12y² - 12y² + 4) - y²
= {12y²(3y² - 1) - 4(3y² - 1)} - y²
= (12y² - 4)(3y² - 1) - y²
= 2(6y² - 2)(3y² - 1) - y²
= (6y² - 2)(6y² - 2) - y²
= (6y² - 2)² - y²
Using identity a² - b² = (a + b)(a - b), we get:
= (6y² + y - 2)(6y² - y - 2)
= {6y² - 3y + 4y - 2}{6y² - 4y + 3y - 2}
= {3y(2y - 1) + 2(2y - 1)}{2y(3y - 2) + 1(3y - 2)}
= (3y - 2)(2y + 1)(3y + 2)(2y - 1)
= (3y - 2)(3y + 2)(2y + 1)(2y - 1) (Answer)
STEP BY STEP EXPLANATION::::::----
STEP 1
Equation at the end of step 1
((36 • (y4)) - 52y2) + 4 = 0
STEP 2
Equation at the end of step
((22•32y4) - 52y2) + 4 = 0
STEP 3
To Factor by Splitting the Middle Term:::--
Factoring 36y4-25y2+4
The first term is, 36y4 its coefficient is 36 .
The middle term is, -25y2 its coefficient is -25 .
The last term, "the constant", is +4
Step-1 : Multiply the coefficient of the first term by the constant 36 • 4 = 144
Step-2 : Find two factors of 144 whose sum equals the coefficient of the middle term, which is -25 .
-144 + -1 = -145
-72 + -2 = -74
-48 + -3 = -51
-36 + -4 = -40
-24 + -6 = -30
-18 + -8 = -26
-16 + -9 = -25 That's it
Step-3 : Rewrite the polynomial splitting the middle term using the two factors found in step 2 above, -16 and -9
36y4 - 16y2 - 9y2 - 4
Step-4 : Add up the first 2 terms, pulling out like factors :
4y2 • (9y2-4)
Add up the last 2 terms, pulling out common factors :
1 • (9y2-4)
Step-5 : Add up the four terms of step 4 :
(4y2-1) • (9y2-4)
Which is the desired factorization
___________________________________
TO Factor as a Difference of Squares::--
Factoring: 4y2 - 1
Check : 4 is the square of 2
Check : 1 is the square of 1
Check : y2 is the square of y1
Factorization is : (2y + 1) • (2y - 1)