-7√5
rewrite 20 as 2^2·5
factor 4 out of 20. negative ∛4(5)-√5
rewrite 4 and 2^2 negative ∛2^2·5-√5
pull terms out from under the radical
-3(2√5)√5
multiply 2 by -3
-6√5-√5
subtract √5 from -6√5
-7√5
the answer is -7√5
The answer is o+ Hope this helped.
In order to solve for the other binomial, it's a hit-and-miss game :) Kind of
We know that in order to get x^2 there has to be an x multiplied by an x
(x + 9) (x (+/-) __)
What multiplied by 9 equals - 36 but also when added to nine equals 5?
The answer would be add 4 each time
To put simple like this
add as normal
2+2=4
add if were positive but keep it negative
-2+-2=-4
at this point it basically turns in to a subtraction problem
2+-2=0
here is another way to look at it. two positives (+) and two negatives (-)
+ +
- -
if there is a negative under it, it is canceled out.
in this there are 5 positives and 3 negatives. each negative will cancel one positive leaving +2 left
+ + + + +
- - -
hope that explains it some what.
