Use substitution to solve for x and y they give us a system of equations here y is equal to negative five x plus 8 and ten x plus two y is equal to negative two so they've set it up for us pretty well they already have y specifically solved for up here so they tell us this first constraint tells us that y must be equal to negative five x plus eight so when we go to the second constraint here everytime we see a y we say well the first constraint tells us that y must be equal to negative five x plus eight so everywhere we see a y we can substitute it with negative five x plus 8 cuz thats what the first constraint tells us y is equal to that i dont want to be repetitive but i really want you to internalize thats all its saying y is that so everytime we see a y in the second constraint we can substitute it with that so lets do it so the second equation over here is ten x plus two and instead of writing a y there and ive said it multiple times already we can write a negative five x plus eight the first constraint tells us thats what y is so negative five x plus eight is equal to negative two now we have one equation with one unknown we can just solve for x we have ten x plus so we can multiply it we can distribute this two into both of these terms so we have two times negative five x is negative ten x and then two times eight is sixteen so plus sixteen is equal to negative two now we have ten x minus ten x those guys cancel out ten x minus ten x is equal to zero so these guys cancel out and we're just left with sixteen equals negative two which is crazy we know that sixteen does not equal negative two this is an inconsistent result and thats because these two lines actually dont intersect and we could see that by actually graphing these lines whenever you get something like some number equaling some other number that they're clearly not equal to that means its an inconsistent result its an inconsistent system and that these lines actually dont intersect so let me just graph these just to make it clear this first equation is already in slope y intercept form so it looks something like this thats our x axis this is our y axis and its negative five x plus eight so one two three four five six seven eight and then it has a very steep mega downward slope every time you move forward one you have to go down five so it 