Question

已知a,b互为相反数,c,d互为倒数,若a不等于0,那么代数式3a+3b+b/a+1/2cd的值是多少

Answer 1

a,b互为相反数 a+b=0 b/a=-1

c,d互为倒数 cd=1

3a+3b+b/a+1/2cd

=3(a+b)+(b/a)+1/2*(cd)

=3*0+(-1)+1/2*1

=-1/2