[" Wle "16" दर्शाइए कि दो रेखाएँ "a_(1)x+b_(1)y+c_(1)=0" और "a_(2)x+b_(2)y+c_(2)=0," जहाँ "b_(1),b_(2)!=],[" (j) सेमांर है यदि "(a_(1))/(b_(1))=(a_(2))/(b_(2))" और (ii) लंब है यदि "a_(1)a_(2)+b_(1)b_(2)=0]