Expected : "1 * 5 = 5\n 2 * 5 = 10\n
                       ^ this space is never in expected

Expected : "1 * 5 = 5\n 2 * 5
                ^   ^       ^  this one is 5 
Got : "1 * -40 = -40\n 2 * -40
           ^^^   ^^^       ^^^ but this is -40?

I guess you also made those changes in the note app then.

I've just erase the "instead" on my note app ^^

@Chrono, it works thank you :)

I don't see how you could possibly obtain this error message

Expected : "1 * 5 = 5\n 2 * 5 = 10\n 3 * 5 = 15\n 4 * 5 = 20\n 5 * 5 = 25\n 6 * 5 = 30\n 7 * 5 = 35\n 8 * 5 = 40\n 9 * 5 = 45\n 10 * 5 = 50

Got : "1 * -40 = -40\n 2 * -40 = -80\n 3 * -40 = -120\n 4 * -40 = -160\n 5 * -40 = -200\n 6 * -40 = -240\n 7 * -40 = -280\n 8 * -40 = -320\n 9 * -40 = -360\n 10 * -40 = -400"

that is not at all what the error messages look like when I run it, for example, you've written "Got :" with two line terminators before it, while the actual output is ", instead got:" with no line terminator, and the expected one is 5 while got is -40, a closing double is missing, spaces appearing out of nowhere ..

this is what they do look like:

Expected: "1 * 5 = 5\n2 * 5 = 10\n3 * 5 = 15\n4 * 5 = 20\n5 * 5 = 25\n6 * 5 = 30\n7 * 5 = 35\n8 * 5 = 40\n9 * 5 = 45\n10 * 5 = 50", instead got: " 1 * 5 = 5\n 2 * 5 = 10\n 3 * 5 = 15\n 4 * 5 = 20\n 5 * 5 = 25\n 6 * 5 = 30\n 7 * 5 = 35\n 8 * 5 = 40\n 9 * 5 = 45\n 10 * 5 = 50"

I copied and pasted your code, removed the space at the end, and passed both sample and attemp tests.

Thank you Chrono, but i've already this option (has many others) and it doesnt work.

Remove that space you've added at the end, and your code will pass.

seems to be impossible to resolve with ruby :/
I've test every possible options...
But on every i'm turning between those results :

Expected : "1 * 5 = 5\n 2 * 5 = 10\n 3 * 5 = 15\n 4 * 5 = 20\n 5 * 5 = 25\n 6 * 5 = 30\n 7 * 5 = 35\n 8 * 5 = 40\n 9 * 5 = 45\n 10 * 5 = 50

Got : "1 * -40 = -40\n 2 * -40 = -80\n 3 * -40 = -120\n 4 * -40 = -160\n 5 * -40 = -200\n 6 * -40 = -240\n 7 * -40 = -280\n 8 * -40 = -320\n 9 * -40 = -360\n 10 * -40 = -400"

or

Expected : "1 * 38 = 38\n2 * 38 = 76\n3 * 38 = 114\n4 * 38 = 152\n5 * 38 = 190\n6 * 38 = 228\n7 * 38 = 266\n8 * 38 = 304\n9 * 38 = 342\n10 * 38 = 380"

Got : "1 * 38 = 38\n 2 * 38 = 76\n 3 * 38 = 114\n 4 * 38 = 152\n 5 * 38 = 190\n 6 * 38 = 228\n 7 * 38 = 266\n 8 * 38 = 304\n 9 * 38 = 342\n 10 * 38 = 380"

Once it doesnt wants the space after the results, and the next time it wants it.

What ???