Which method do you use to solve #7x^2 + 8x + 100#?
2 Answers
A quadratic equation is simply another way of solving a problem if the solution cannot be factored logically.
First we can start with some quick review:
Let’s say we have the equation
To begin, we can state the factors of the first term,
Now we can check and see if any of the factors can combine in order to get a
From our factors we can use a -1 and a 3 to get +2. Therefore,
However , when the logical factorization seen above is not possible, we can plug our numbers into the quadratic equation .
After our a, b, and c values are found we can plug them into the actual quadratic equation.
Note : This equation may look intimidating, but as long as you follow factoring rules, you should have no problem. It’s totally normal to come out with an answer containing square roots.
We do not "solve" expressions.
Perhaps you want to know how to solve the equation
Or perhaps you want to know how to factor the expression
In order to do the second for this expression, we'll have to do the first. That's because this expression is irreducible using real, rational coefficients.
Solve:
Spend a little time factoring, but not too much, because we know we can always solve by the quadratic formula.
For the equation we're working on:
Note
Simplifying sqrt(2736) is not trivial.
So
Now that we know the zeros of