The slope of the linear equation y=x + 6 is 1. When with a variable with a coefficient of 1, you do not need to write out 1. If it were zero, there would be no variable in the equation. It just stands on its own without the written coefficient. 1x=x. A does not make sense because x times x is x^2. in C, as i said before, there would just be no x and the equation would be y=6. And 6 is the y-intercept since it is in the place of b of y=mx+b.