Question

The product of two numbers is 240.The first number is less then the second number.Which equation can be used to find x,the lesser number?

Answer 1

Let's call the lesser number x and the other one x+8

Explanation:

The product x⋅(x+8)=240→

Or:  x2+8x=240→

We can rework this by subtracting 240 from both sides:

x2+8x−240=0

Now we factor −240 into two factors that add up to 8
After some trying we find 20and−12

The equation turns into

(x+20)(x−12)=0

→x=−20orx=12

So the pairs of numbers will be:

−20and−12 or +12and+20