Question

hlo frnds, gm guys .
x-y=18
xy =36

find the value of x and y​

Answer 1

Answer:

xy = 36

x = 36/y

x - y = 18

36/y - y = 18

36 - y² / y = 18

36 - y² = 18y

y² - 18y -36 = 0

y = 18 +- √ 18² - 4(1)(-36)/2(1)

= 18 +- √ 324 + 144 /2

= 18 +- √468 /2

Answer 2

Answer:

x-y=18

x=18+y.......... (1)

xy=36............ (2)

Substituting the value of x in equation (2) we get,

(18+y) y=36

18y+y²=36

y²+18y-36=0.. ...... (Quadratic equation)

comparing the above equation with ax²+bx+c=0

therefore, a=1 , b=18 andc=-36

b²-4ac=(18) ²-4(1) (-36)

=324+144

=468

x=-b±√b²-4ac/2a

=-18±√468/2

therefore x = 18+√468/2 or 18-√468/2

by substituting the value of x in equation one we get the value of y