Question 890156
let the two numbers be x and y
(x y)/2=15.....1
x-2y=21.....2
from.equation 1 equate both sides
x y=2times 15
x y=30
from equation 2 make x the subject of the formula
x=21 2y....3
put x in equation 2
21 2y y=30
21 3y=30
collect like terms
3y=30-21
3y=9
divide both sides by 3
y=3
put y in equation 3
x=21 2(3)
x=27