Question

ab × cd = bbb

Answer 1

= ( 10a+b ) x ( cx10+d)= 100b+10b+b

=10ac+10ad+10bc+10bd-100b-10b-b=0

=10(ac+ad+bc+bd-10b)-b=0

=10ac+(c+d)+b(c+d)-9b)-b=0

=10+ab + cd -b = 0

Answer 2

=(10a+b)x(cx10+d)=100b+10b+b

=10ac+10ad+10bc+10bd-100b-10b-b=0

=10(ac+ad+bc+bd-10b)-b=0

=10(a(c+d)+b(c+d)-9b)-b=0

=10 (a+b)(c+d)-b=0