What numbers can you multiply to get 21 and add to get 4?

Answer 1

I think one or both of those have to be negative.

-3 + 7 = 4

-3 x 7 = -21

3 + -7 = -4

3 x -7 = -21

7 x 3 = 21

7 - 3 = 4

It also works if you subtract.

Answer 2

To find two numbers that multiply to 21 and add up to 4, we can set up a system of equations. Let's call the two numbers x and y. We have the equations xy = 21 and x + y = 4. By solving these equations simultaneously, we find that the two numbers are 3 and 7. This is because 3 * 7 = 21 and 3 + 7 = 10, which does not satisfy the condition x + y = 4.