Find the value of d such that the system of equations
-10x + 15y = -17
dx +12y = 8
Does not have a solution
Whatever value of 'd' makes the lines' slopes the same would be what you are looking for .....same slope lines are parallel and do not intersect.
Place each line into y = mx + b form m is the slope
15y = 10x - 17
y = 2/3 x - 17/15 slope = 2/3 so we need a value of d to make slope of second line = 2/3
dx + 12y = 8
12 y = - dx + 8
y = - d/12 + 2/3 we need -d/12 = 2/3 so d = -8