How is an equation in quadratic form usually solved?
- By dividing out every variable
- By squaring both sides once
- By graphing both sides first
- By substituting one new variable
Show answer and solution
Correct answer: D. By substituting one new variable
1. An equation is in quadratic form when squaring the variable part of the middle term gives the first term.
2. Letting a new variable u stand for that middle variable part turns it into an ordinary quadratic.
3. Solve that quadratic by any usual method.
4. Then put the original expression back in place of u and finish solving.
_Source: OpenStax Intermediate Algebra (CC BY 4.0), section 9.4 Solve Quadratic Equations in Quadratic Form_