(-7.42)*(-2/19)+(-9.24)*(-2/19)+8.33*(-4/19)
6个回答

(-7.42)*(-2/19)+(-9.24)*(-2/19)+8.33*(-4/19)

=(-7.42)*(-2/19)+(-9.24)*(-2/19)+8.33*(-2/19)*2

=(-7.42-9.24+8.33*2)*(-2/19)

=0*(-2/19)

=0

(7-x)/4-(x-1)/3=x+1

3(7-x)-4(x-1)=12(x+1)

21-3x-4x+4=12x+12

x=13/19