Question

Question 2 someone answer please

Answer 1

Hello dear,
1/(a+b+x)=1/a + 1/b + 1/x

1/(a+b+x) -1/x = 1/a + 1/b

x-(a+b+x)/x(a+b+x) = a+b/ ab

-1(a+b) /x(a+b+x) = a+b/ ab

-1(a+b)/(a+b) = x(a+b+x)/ab

-1=x(a+b+x) / ab

-ab= (a+b)x + x2

so, x2 + (a+b)x +ab = 0

now, A = 1, B=(a+b) C= ab..

so, D = B2 - 4AC

  =(a+b)2 - 4ab

  = (a-b)2

so, x = (-B + root D)/2A  and (-B-root D)/2A

  = -a-b+a-b /2*1   and  -a-b-a+b /2*1

  = -2b/2 and -2a /2

so,x = -b or -a...answer,,, :)

(2). Distance formula
x₁=9,x₂=3 y₁=3,y₂=k
=>root[(x₂-x₁)+(y₂-y₁)]
now pu the values,
10²=(3-9)²+(k-3)²
=>100=36+k²+9-6k
=>k²-6k-55=0
=>k²-11k+5k-55=0
=>k(k-11)+5(k-11)=0
=>(k+5)(k-11)=0
=>k=-5 & k=11

Hope its help you dude, :-)