Sometimes the left side may not be obviously factorable. You can always use
the quadratic formula. Just plug the coefficients a, b, and c from ax^2 + bx + c =
0 into the formula:
To solve x^2 + 4x + 2 = 0, plug a = 1, b = 4, and c = 2 into the formula:
QUADRATIC FORMULA
If ax^2 + bx + c = 0, then“IN TERMS OF”
So far in this chapter, solving an equation has meant finding a numerical
value for the unknown. When there’s more than one variable, it’s generally
impossible to get numerical solutions. Instead, what you do is solve for the
unknown in terms of the other variables.