Posted by Alyssa on .
So I am doing my algebra home work and I get stuck on these three problems.
x^219x+72 from there idk what to do because nothing multiplies up to 72 and adds up to 19.
Same for this one.
x^225x+48
And
x^2+990
(X+15) (x6)

algebra 2 
Reiny,
I am assuming you are factoring ?
for x^2  19x + 72 there are no factors with rational numbers
(I found the discriminant b^2  4ac to be 649, which is not a perfect square, thus no factors)
x^2  25x  90
same thing, b^24ac = 985 , no factors
I assume a typo in the 3rd and you meant:
x^2 + 9x  90
which does factor to (x+15)(x6)