Question

Answer is 13.
please explain.​

Answer 1

Step-by-step explanation:

let us assume R stands for square root. Then the given expression looks as below.

(R7+R5)

----------- = a+bR35

(R7-R5)

To find the values of a and b, we need to rationalize the denominator R7-R5.

(R7+R5)       (R7+R5)

(R7-R5)        (R7+R5)

7+5+2R7R5

7-5

12+2R35

2

6+R35 = a+bR35

Hence a=6 and b=1

Answer 2

Answer:

Step-by-step explanation:

=>√7-√5/√7+√5×√7-√5/√7-√5

=>(√7-√5)^2/(√7)^2-(√5)^2

=>(√7)^2+(√5)^2-2×√7×√5/7-5

=>7+5-2√35/2

=>12-2√35/2

=>2(6-√35)/2

=>6-√35=a+b√35

Then, a=6 and b=-1

(6)^2+4×6×-1+(-1)^2

=>36-24+1

=>37-24=13