Question

If a2+b2-4(a+b)= -8,then the value of (a-b) is:

Answer 1

given a2+b2-4(a+b)=-8
now a2+b2=4 (a+b)-8________(1)
now we know that:-
a2+b2=(a+b)(a-b)
4 (a+b)-8=(a+b)(a-b) [from eqn 1]
4 (a+b)/(a+b)=(a-b)-8
4=(a-b)-8
(a-b)=4+8=12 therfore (a-b)=12