let 'x' be the number
'y' be the other number
x + y = 11 ---equation 1
xy = 30 ----equation 2
from equation 1
x + y = 11
x = 11 - y ---equation 3
substitute equation 3 to equation 2
xy = 30
(11 - y)(y) = 30
11y - y² = 30
y² - 11y + 30 = 0
(y - 5)(y-6) = 0
y = 5 , y = 6
taking both values as values of x and y
therefore the two numbers are 5 and 6
