Question

Find three consecutive even integers such that the sum of the smallest and twice the second Is twenty more than the third

Answer 1

you can get these equation from the question:
let x,y,z be the 3 consecutive numbers.

x + y -z = 20,
z-y = 1
y-z = 1

then try solving them:
y = z - 1
x = y - 1, x = (z-1) -1

then put them in the first equation:
(z-2) + (z-1) - z = 20
z - 3 = 20
z = 23

so you get the three numbers which are 21,22 and 23