Question

a2 - a - 20

Answer 1

\[a^2-a-20\]?

Answer 2

what do you need to do?

Answer 3

factorize?

Answer 4

put it in grouping

Answer 5

\[(b+p)(b+q)=b^2+(p+q)b+pq\]

you need to find \(p,q\) such that

\(p+q=-1\) and \(pq=-20\)

Answer 6

inotherwords;
you need to find the two numbers that

add to give negative one
and
multiply to give negative twenty

Answer 7

pairs of factors of negative twenty are\[-20=(\pm1)(\mp20),(\pm2)(\mp10),(\pm4)(\mp5).\]

can you find the pair that add to give negative one?