- 怎样更快的求出两元一次方程中代入法的解??快点哦……急死了!
- 快点哦……急死了!
- 怎样更快的求出两元一次方程中代入法的解?
ax+by = c ......(1)
mx+ny = p ......(2)
(1)--->by = c-ax ...........移项
--->y = c/b-(a/b)x ......两边同除以b
代入(2): mx + n[c/b-(a/b)x ] = p
--->[m-an/b]x = p-nc/b
--->x = [p-nc/b]/[m-an/b] = (pb-nc)/(mb-an)