1.x取哪些非负整数时,3x-2/5的值大于2x+1/1的差2.若方程组{4x-3y=k 2x=3y=5的解满足x+y≤k求k取值范
问题描述:
1.x取哪些非负整数时,3x-2/5的值大于2x+1/1的差2.若方程组{4x-3y=k 2x=3y=5的解满足x+y≤k求k取值范
急
答
4x-3y=k ①
2x+3y=5 ②
①-②×2得:
4x-3y-4x-6y=k-10
-9y=k-10
y=-(k-10)/9
①+②得:
4x-3y+2x+3y=k+5
6x=k+5
x=(k+5)/6
因为x+y