Question

若关于x,y的方程组3x-4y=m x+2y=m-5的解x与y互为相反数,则m的值为

Answer 1

3x-4y=m ----------------(1)

x+2y=m-5 ----------------(2)

x=(3m-10)/5

y=(2m-15)/10

x=-y

(3m-10)/5=-(2m-15)/10

m=35/8