Solve the problem.
-The product of a number and 3 less than the number is 18. Find the number.
A)-6 or 3
B)-7 or 2
C)-3 or 6
D)-2 or 7

Question

Quizplus · Accepted Answer

Let the number be x. Then according to the problem, we have x(x-3) = 18. Simplifying this quadratic equation, we get x^2 - 3x - 18 = 0, which factors as (x-6)(x+3) = 0. Therefore, the possible solutions for x are x = 6 or x = -3. So the answer is choice C, which gives both possible values for x. Let's call the number "x". According to the problem, we can set up the equation: 
x(x-3) = 18 
Expanding the equation: 
x^2 -3x = 18 
Moving all terms to one side: 
x^2 -3x -18 = 0 
Now we can use factoring or the quadratic formula to solve for x. Factoring gives us: 
(x-6)(x+3) = 0 
So, x could be either -3 or 6.

Solve the Problem. -The Product of a Number and 3 Less Than the Less