Walter is back in his lab doing experiments. For his new experiment, he needs 2 parts of water for every 8 parts of salt
If he has 7.5 parts of water, how many parts of salt does he need?

Abit confused about what you mean, but i think you might be referring to slope intercept form: y = mx + bin that case b, or the y intercept is already given.(0,-1)find the slope by using the formulay2 - y1/x2 - x1the final slope will be 4/2, equivalent to 2.now your equation should look like thisy = 4/2x -1sorry if this didn’t you out!