Ab¯¯¯¯¯¯ has endpoints a(2, 4) and b(8, y). if ab is 10, what is the value of y?

10=✓(36+(y-4)²)

10=✓36+y²-8y+16

10=✓y²-8y+52

100=y²-8y+52
y²-8y-48=0

(y+4)(y-12)=0

y=-4 or y=12

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!