Determine the standard form of the equation of the line that passes through (-8,-6) and (-4,9)

The standard formula using 2 arbitrary points is:
A(x1, y1)
B(x2, y2)

y-y1 = m(x-x1)
where m = (y1-y2)/(x1-x2)

Solving our problem:
m = 9-(-6)/-4-(-8)
m=15/4

y+6=15/4(x+8)
4y+24=15x+120

The standard form of the equation is: 15x-4y+96=0

Definitely