What equals 10 in multiplicattion? ?

5×2=10 1×10 those two factors equal 10. O cant think of anymore

1*10
5*2
And the other way around for those^ 

A. p = 2(l + w)p/2 - l = ww = p/2 - l b. while isolating the variable w in the equation, i first divided both sides by 2 and then i subtracted l from both sides. i hope this .

Ya i could just need to know what type of math