Question

Find the value of 8ab(a2+b2) when a+b=root over 5 and a-b= root over 3

Answer 1

(a+b)2 =a2+b2+2ab n( a-b) 2 = a2+b2 -2ab
from these formulas;;;
8ab(a2+b2)= 8ab((a+b)2-2ab))
as a+b=root over5;;so  eq is 8a(5-2ab)
=40ab-16ab
=24 ab(((((((from eq's a+b =root 5 and a-b =root 3<<solve the equations>>))
=12 (((substitute the values of a n b ))
therefore the answer is 12//