4y ³-2y ²-4y +2 factorise
Answers
please mark as brainiest
Final result :
2 • (y + 1) • (y - 1) • (2y - 1)
Step by step solution :
Step 1 :
Equation at the end of step 1 :
(((4 • (y3)) - 2y2) - 4y) + 2
Step 2 :
Equation at the end of step 2 :
((22y3 - 2y2) - 4y) + 2
Step 3 :
Step 4 :
Pulling out like terms :
4.1 Pull out like factors :
4y3 - 2y2 - 4y + 2 =
2 • (2y3 - y2 - 2y + 1)
Checking for a perfect cube :
4.2 2y3 - y2 - 2y + 1 is not a perfect cube
Trying to factor by pulling out :
4.3 Factoring: 2y3 - y2 - 2y + 1
Thoughtfully split the expression at hand into groups, each group having two terms :
Group 1: -2y + 1
Group 2: 2y3 - y2
Pull out from each group separately :
Group 1: (-2y + 1) • (1) = (2y - 1) • (-1)
Group 2: (2y - 1) • (y2)
-------------------
Add up the two groups :
(2y - 1) • (y2 - 1)
Which is the desired factorization
Trying to factor as a Difference of Squares :
4.4 Factoring: y2 - 1
Theory : A difference of two perfect squares, A2 - B2 can be factored into (A+B) • (A-B)
Proof : (A+B) • (A-B) =
A2 - AB + BA - B2 =
A2 - AB + AB - B2 =
A2 - B2
Note : AB = BA is the commutative property of multiplication.
Note : - AB + AB equals zero and is therefore eliminated from the expression.
Check : 1 is the square of 1
Check : y2 is the square of y1
Factorization is : (y + 1) • (y - 1)
Final result :
2 • (y + 1) • (y - 1) • (2y - 1)