The sum of two numbers is 12. the productof those same numbers is -64. find the numbers

Let the first number be A. and the second number B.
A + B=12equation1 and
A ×B =-64eqn2

from eqn1,
A =12 - B
so put A=12-B into eqn 2

(12-B) ×B=-64
.12B-B^2=-64
B^2-12B-64=0
now use calculator to find the answer.
u will get two answers, but u haven't finished yet. if B is = X,
put Xinto A=12-B
to find the value of A.
and so the same for the second number.