Question

calculati
27-25+23-21+....+7-5+3-1

Answer 1

27-25+23-21+...+7-5+3-1 =

= 2+2+2+...+2+2 {de (27+1)/4 = 7 ori}

= 2•7

= 14

Answer 2

27-25+23-21+...+7-5+3-1=

=(27-25)+(23-21)+...+(7-5)+(3-1)=

=(4*6+3)-(4*6+1)+(4*5+3)-(4*5+1)+...+(4*1+3)-(4*1+1)+(4*0+3)-(4*0+1)=

=2*7=

=14