Question

Prove that the product of -1 and -1 equals to +1

Answer 1

Multiplying 2 negatives will equal a postive.

Answer 2

Multiplying two positive numbers or two negative numbers always equal a positive number
Multiplying a positive number and a negative number always equals a negative number

Example

1- 2x2=4. -3x(-4)=12

2- -2x2=(-4). -3x4= (-12)

Hope this helps