The endpoints of jk are j(–25, 10) and k(5, –20). what is the y-coordinate of point l, which divides jk into a 7: 3 ratio

The correct answer for this question is this one: (-4, -11)
In order to solve this,

Let k1 = 7/10 = fraction of the first part
Let k2 = 3/10 = fraction of the second part

Then, use solve for x and y

x = (k1(x2) +k2(x1)) / (k1+k2)
y = (k1(y2) +k2(y1)) / (k1+k2)

x = (7/10 * 5 + 3/10 * -25) / (7/10 + 3/10 )
x = -8 / 2
x = -4

y = (7/10 * -25 + 3/10 * 10) / (7/10 + 3/10)
y = -14 + 3
y = -11

Hope this helps answer your question. Have a nice day!