Question

How do you solve x4+200=102x2?

Answer 1

Factoring will get you there. This is a modified case of something you probably know well.

Answer 2

Should i move the 102x2 to the left?

Answer 3

Good start.

Answer 4

then factor out the X2 right? then what i always get stuck here

Answer 5

Now you have \[x^{4} - 102x ^{2}+ 200 = 0\]. What if it was squared and first power instead of powers 4 and 2? Could you factor?

Answer 6

Okay so factor out the X2 then it would be x2(x2-102)+200

Answer 7

That is right in a way, but you should do the type of factoring that gives you a pair of parentheses instead of just getting a greatest common factor.

Answer 8

okay... so what method would be the best?

Answer 9

(x2 )(x2 ) would be how it would look roughly. You then have to determine what would make each parentheses = 0

Answer 10

okay thanks