Question

{x+2y=10
{6y=-3x+30
Help please

Answer 1

Explanation:

x+2y=10

6y=-3x+30

~~~~~~~~~~~~~~~~

x =10 -2y

substitution

6y=-3x+30

6y=-3(10 -2y)+30

6y = -30 + 6y + 30

6y = 6y

everything disappears.... that means the lines are "the same line"

"co-incident" ... "infinite solutions"

Note" if you ended up with something like 3=0 then the lines are parallel