Question 485714
x+y=450 (equation 1)
x-20=2y (equation 2)

Rearrange equation 2: x-2y=20 (equation 2)

Equation 1 - Equation 2:
3y=430
y=430/3

Substitute:
x+430/3=450
3x+430=1350
3x=920
x=920/3