SOLUTION: -4r squared + 100s squared How do you factor this polynomial Is the answer -4(r-5)(r-5s)

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: -4r squared + 100s squared How do you factor this polynomial Is the answer -4(r-5)(r-5s)      Log On


   

Question 282108: -4r squared + 100s squared How do you factor this polynomial
Is the answer -4(r-5)(r-5s)
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
This is a difference of squares
a^2-b^2=(a+b)*(a-b)
-4r^2+100s^2
lets turn it around
100s^2-4r^2
(10s-2r)(10s+2r)
we could also factor out the 4
4*(25s^2-r^2)
4*(5s-r)*(5s+r)
or
in its original form
-4 (r-5s) (r+5s)
you forgot one of the s's
so we have several forms
(10s-2r)(10s+2r)
4*(5s-r)*(5s+r)
-4 (r-5s) (r+5s)
all produce the same when foiled