Final Answer:
Equation D: -6x + 3 = 0 has only one solution.
Step-by-step explanation:
To determine which equation has only one solution, we can solve each equation for x.
A. x-5 = -1
x = 4
B. .6 -2x = 8
-2x = 7.4
x = -3.7
C. 15x + 10= 10
15x = 0
x = 0
D. -6x + 3 = 0
-6x = -3
x = 1/2
Therefore, the only equation that has only one solution is D: -6x + 3 = 0.