Question

If x2 + y2 = 100, and xy = 18, find the value of x - y.

Answer 1

8

Answer 2

see x2+y2-2xy=(x-y)2..
you can substitute the values to get your answer

Answer 3

wrong

Answer 4

just express x=18/y and replace it in the other eq

Answer 5

the answer is 8

Answer 6

8 is right

Answer 7

there are two answers.

Answer 8

+8,-8 then..

Answer 9

yes right

Answer 10

so you get it how to solve?

Answer 11

im on my next problem now

Answer 12

okay.
you get this right no?

Answer 13

(x-y)^2=x^2-2xy+y^2=x^2+y^2-2xy=(100)-2(18)=100-36= 64

take square root of both sides
x-y= plus or minus 8