If 7 is one solution of the equation x^2 + 3x + k = 10, where k is a constant, what is the other solution?	Options:
A) -7  B) -4  C) -3  D) 1  E) -10
The phrase “7 is one solution of the equation” means that one value of x is 7. Thus, we first must plug 7 for x into the given equation to determine the value of k. So we have   7^2 + (3)(7) + k = 10   49 + 21 + k = 10   70 + k = 10   k = -60   Next we plug -60 into the given equation for k and then solve for x.   x^2 + 3x – 60 = 10   x^2 + 3x – 70 = 0   (x+10)(x-7) = 0   x = -10 or x = 7   Thus, -10 is the other solution. Answer -10.
<result>E</result>
If 7 is one solution of the equation x^2 + 3x + k = 10, where k is a constant, what is the other solution?