Find the product and check for equality: 4 `xx` 51 and 51 `xx` 4

Find the product and check for equality: 18 xx (-5) and (-5) xx 18

Find the product and check for equality: 31 xx (-6) and (-6) xx 31

Find the values of the following and check for equality: (-6) xx (4 + (-5)) and ((-6) xx 4) + ((-6) xx (-5))

Find the product of the following: (-20) xx (-45)

Find the product of the following: (-9) xx (-8)