y = mx + b, where m is the slope, and b is the y-intercept. If we were to consider a line of best fit that would represent all these points with a linear line, it'd cross the y-axis with a y-value of 10, so we can fill in y = mx + b to y = mx + 10. Now, it runs down from left to right, so we know the slope must be negative. The only equation that fits this description is y= -3/4x + 10