How do you solve #c^ { 2} - 30c - 216= 0#?
2 Answers
Explanation:
Factor,
Solve,
The solution set is {-6, 36}
Explanation:
The equation is a quadradic equation with a = 1, b = -30, and c = -216 (note this c is not the same c as the unknown quantity.)
One method of solving for c in the equation is to complete the square. This method only works if a = 1 or on an equation that you have done some manipulation on in order to make a = 1 (usually dividing both sides of the equation by a).
The complete the square method of solving a quadratic equation for its unknown is to add
In our case,
Starting with the original equation:
Adding, then adding, then subtracting
Then factoring our newly formed perfect square:
Then continue to solve for c:
Which implies that