Can you help me with this math problem?
Find the x intercepts for the graph of the equation.
x^{ 2}  x  12 = 0
Thanks alot!
Laura
Hi Laura,
I think the original problem was
Find the x intercepts for the graph of the equation y = x^{ 2}  x  12.
The x intercepts are the points where y = 0 so the problem can be restated
What is x if x^{ 2}  x  12 = 0?
One way to answer this question is to factor the left side of the equation above.
Why factor? Stay with me, you will see soon.
x^{ 2}  x  12 = (x  4)(x + 3) and hence the problem is
What is x if (x  4)(x + 3) = 0?
Having the equation in this form, "the product of two factors is zero" tells us a lot.
If the product of two numbers is zero, then at least one of the numbers must be zero.
Thus either x  4 = 0 or x + 3 = 0. In the first instance x = 4 and in the second, x = 3.
I hope this helps,
Penny
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