Question

How to solve question no. 15 sub question 5 and question no. 16,17

Answer 1

15)A +b =9 ...a
A -b =5......b
From equation a and b we get
7+2=9
7-2 =5
So here a =7
B=2
4ab =4*7*2=56
16))X square +1/x square =23
Find x+1/x
Squaring x+1/x
(X +1'x ) square
X square +1/x square +2
23+2=25
X square +1/x square =25
X +1/x =5
17)) a square + b square =117
Ab =54
(a+b) square
A square + b square +/-2ab(by using identity 1 and 2)
117+2*54
117+108/117-108
225/9
A square + b square =225
A +b =15
A square -b square =9
A -b =3
So a +b/a-b
15/3=5
:) hope it helps youu