已知二分之a等于三分之b等于四分之c,a+b+c=27,求a-2b-2c的值

a/2=b/3=c/4=t a+b+c=2t+3t+4t=9t=27,t=3 a-2b-2c=2t-6t-8t=-12t=-12*3=-36