If 6 is one solution of the equation x^2 + 3x + k = 10, where k is a constant, what is the other solution?
Choose the correct choice from the following:
A) -7
B) -4
C) -3
D) -9
E) 6
The phrase “6 is one solution of the equation” means that one value of x is 6. Thus, we first must plug 6 for x into the given equation to determine the value of k. So we have   6^2 + (3)(6) + k = 10   36 + 18 + k = 10   54 + k = 10   k = -44   Next we plug -44 into the given equation for k and then solve for x.   x^2 + 3x – 44 = 10   x^2 + 3x – 54 = 0   (x+9)(x-6) = 0   x = -9 or x = 6   Thus, -9 is the other solution. Answer -9.
<result>D</result>
If 6 is one solution of the equation x^2 + 3x + k = 10, where k is a constant, what is the other solution?