Question

what is the solution to the following

3x + 3y = 10

-9x - 9y = -30

Answer 1

-3*(1)=(2)
therefore infinitely many solutions

Answer 2

3(3x+3y = 10) gives 9x + 9y = 30
-9x-9y=-30 we're eliminating here
0 = 0
You have an infinite number of solutions that will work.

Answer 3

The second equation is just the first equation multiplied by -3, hence they are the same equation and you'll have an infinite number of solutions.

Answer 4

3x + 3y = 10
3x = -3y+10
\[x=\frac{ -3y+10 }{ 3 }\]Then substitute this into the 2nd equation