Respuesta :

10x+10y=1
x=y-3
10(y-3)+10y=1
10y-30+10y=1
20y=31 
y=31/20
MissPhiladelphia
By substitution method, we can substitute the lower equation to x of the top equation as follows:

10 (y - 3) + 10y = 1

Then, we solve for y

10 (y - 3) + 10y = 1
10y - 30 + 10y = 1
20y = 31
y = 31/20 <------ second option