有些二元一次方程组有特殊的结构,若选择适当的方法,可以使这些方程组的求解变得简单易行.一、可整体换元的方程组的解法例1解方程组3(x+y)-4(x-y)=1,x+y2+x-6y=1.分析从形式上看,这个方程组比较复杂,应先将每一个方程都进行化简,化成二元一次方程组的一般形式,然后再选择代入法或加减法来求解.但是,通过观察可以发现,方程组中两个未知数出现的形式只有(x+y) Some binary linear equations have a special structure, if you choose the appropriate method, you can make the solution of these equations becomes easy. First, y) -4 (xy) = 1, x + y2 + x-6y = 1. Analysis Formally speaking, this system of equations is rather complicated, and each equation should be simplified to form a system of linear equations General form, and then choose the method of substitution or addition and subtraction to solve, but by observing, we can see that the two unknowns in the system of equations appear in the form of (x + y)