# Exponents - Solve 3rd Degree Equation

How would I solve for 7x^3-4x^2=3x^3-11?
Do I add the exponents together?

### Comments for Exponents - Solve 3rd Degree Equation

 May 03, 2011 Solve 3rd Degree Equation by: Staff The question: How would I solve for 7x^3-4x^2=3x^3-11? Do I add the exponents together? The answer: No. You cannot ad the exponents together. 7x³ - 4x² = 3x³ - 11 7x³ - 3x³ - 4x² = 3x³ - 3x³ - 11 7x³ - 3x³ - 4x² = 0 - 11 7x³ - 3x³ - 4x² = - 11 4x³ - 4x² = - 11 4x³ - 4x² + 11 = - 11 + 11 4x³ - 4x² + 11 = 0 Standard form of the cubic equation 4x³ - 4x² + 11 = 0 Graphing – can find the real root by graphing Factoring – this cubic equation cannot be factored easily. It is obvious that has complex roots. Using the CUBIC FORMULA is the answer. It is similar to the quadratic formula, but it must be solved in steps. Using the cubic formula is complex. An explanation of how to use Excel to solve this problem can be down loaded here: http://web.mit.edu/10.213/www/extra/solvecubic.pdf The solution to your problem has 1 real root and 2 complex roots. They are: x1=-1.13494125358 x2=1.06747062679 +j1.13293396259 x3=1.06747062679 -j1.13293396259 Thanks for writing. Staff www.solving-math-problems.com