if x^2 - y^2 = 160 & x-y=8 then the average of x & y is.....

Question

explain the sum.......... easily.....

Answer 1

Given:     x²-y² = 160     and   (x-y)=8

 

   x²-y² = (x-y)(x+y)          [factor]

   160 = 8(x+y)             [substitute givens]

    20 = (x+y)                [divide both sides by 8]

 

Average:   (x+y)/2 = 20/2 = 10       [no need to find x or y]

Answer 2

Hi Dhana,

 

X²  - Y² =160

using factorization,

 

(X+Y)(X-Y)= 160,   given X-Y=8

 

(X+Y)*8=160

X+Y=20

 

adding two equations,

X+Y=20

X-Y=8,

we get 2X =28

            X=14

           Y= 6

Average of X & Y is 14+6/2 = 20/2=10

       

Answer 3

(1/2)(p-q) = (3/10)(p+q)

(1/2)p - (1/2)q = (3/10)p - (3/10)q

(1/5)p = (4/5)q

p = 4q

q/p = 1/4

 

q = x/100•p

x = 100(q/p)

 

x = 100(1/4)  = 25.