Question

What two numbers multiplies to 36 and add to negative 21

Answer 1

Factor 36 and add them, make sure both are negatie
1+36=37, nope
2+18=20 nope
3+12=15,nope
4+9=13, nope
6+6=12, nope

the closest one is 20

I hope you meant adds to -20, because if you did, then answer is -2 and -18

if you did mean 36 and adds to -21, then the numbers are $\frac{-21-3 \sqrt{33} }{2}$ and $\frac{-21+3 \sqrt{33} }{2}$, aprox -19.1168 and  -1.8831