I am the lcm of two numbers whose sum is 40 and whose difference is 10

Answer 1

We need a bit of algebra...

(1) X + Y = 40 (two numbers whose sum is 40)

+

(2) X - Y = 10 ( two numbers whose difference is 10)

=

2X = 50

=> X = 25

hence 25 + Y = 40 => Y = 15

multiples:

15,30,45,60,75,90

25,50,75,100

LCM (15, 25) = 75

Answer 2

x+y=40

x-y=10

2x=50

x=25

y=15