Question

What numbers add up to 3 & multiple to 10

Answer 1

Well, factors of 10 are:
1 and 10
and
2 and 5

Those don't add up to three. However, if it was -10, then 5 and -2 would add up to three.

Answer 2

There are no real numbers that can do that job.

The numbers are

1.5 + i √7.75
and
1.5 - i √7.75

These are called 'complex numbers'. The symbol ' i ' stands for √-1 .

==================================================

If either the ' 3 ' or the ' 10 ' was actually supposed to be negative,
then the two numbers would be 2 and -5 .