Factorise: x²+4abx-(a²-b²) ²
Answers
Step-by-step explanation:
What is the factorisation of (a−2b)2−4a+8b?
A2A
(a−2b)2−4a+8b
=(a−2b)(a−2b)−4(a−2b)=(a−2b)(a−2b−4)
=(a−2b)(a−2(b+2))
Answer:
In order to factor this you are looking for:
(x−m)(x−n)=x2+4abx−(a2−b2)2
Where m and n are the roots of our equation.
For this, let's work with the quadratic formula. I'm going to do a partial substitution and see where it takes me:
−(4ab)±d−−√2⋅1
=−2ab±d√2
d being the determinant. Okay. What then is d?
d=(4ab)2–4(1)(−(a2−b2)2)
=16a2b2+4(a4–2a2b2+b4)
=4a4–8a2b2+16a2b2+4b4
=4a4+8a2b2+4b4
=4(a2+b2)2
And let's just figure out the ± portion of the equation:
d√2=4(a2+b2)2√2 v
=a2+b2
Which makes our roots:
−2ab+a2+b2=(a−b)2
−2ab−a2+b2
=−(a2+2ab+b2)=−(a+b)2
And that makes our factorization:
x2+4abx−(a2−b2)2
=(x−(a−b)2)(x+(a+b)2)
Step-by-step explanation:
hope it will help you