X+X+X+(X-1)+(X-2)+(X-3)+(X-4)=10(X-3)+(X-4)
问题描述:
X+X+X+(X-1)+(X-2)+(X-3)+(X-4)=10(X-3)+(X-4)
答
7x-10=11x-34
-4x=-24
x=6