Friday

July 25, 2014

July 25, 2014

Posted by **Kyle** on Wednesday, December 8, 2010 at 1:36am.

find the real solutions of the equation

x to the 4th power minus 20x squared plus 64 equals 0

- Algebra -
**drwls**, Wednesday, December 8, 2010 at 2:17amIt is easier to do algebra if you write equations like that as follows:

x^4 -20x^2 +64 = 0

Make a substitution y = x^2 and you have

y^2 -20y +64 = 0

which can be factored to give

(y -16)(y-4) = 0

The solutions are:

y = x^2 = 4 or 16

So

x = +2, -2, +4 and -4.

**Related Questions**

Honors Algebra 2 - i have no clue how to solve this!! the problem is... 20x^3 - ...

Math - What is x to the fourth power minus 20x plus 64 equals 0

algebra 2 - I am so stuck on this factoring thing. how do you solve: 1)15a(...

algebra - determine the nature of the solutions of the equation, one real ...

algebra again - Write an equation that passes through the points (4, 3) and (2...

math - Have 2 questions: 1. Factor Trinomial competely x^2 + 8x + 53 (reads as x...

how many solutions are real? - hi, I am stuck on this question. y=x^2+4x and y^2...

algebra ll - solve 3 plus(2y minus 1)> equals 1 my ans. is (2y minus 1) ...

math - write this equation in standard form. y=1/2x2+12x-8 y equals one half x ...

Algebra - I need help solving the trinomial (x squared minus four x plus ...