How do you factor -7x^4 + 567x^27x4+567x2?

1 Answer
Oct 24, 2015

Separate out the common factor -7x^27x2 then use the difference of squares identity to find:

-7x^4+567x^2 = -7x^2(x-9)(x+9)7x4+567x2=7x2(x9)(x+9)

Explanation:

Both -7x^47x4 and 567x^2567x2 are divisible by -7x^27x2, so separate it out as a factor to find:

-7x^4+567x^2 = -7x^2(x^2-81) = -7x^2(x^2-9^2) = -7x^2(x-9)(x+9)7x4+567x2=7x2(x281)=7x2(x292)=7x2(x9)(x+9)

...using the difference of squares identity

a^2-b^2 = (a-b)(a+b)a2b2=(ab)(a+b)