【知识要点分析】一次函数与一元一次方程的关系一个一元一次方程一般部可以转化为ax+b=0 (a、b为常数,a≠0)的形式,所以解一元一次方程可以转化为：当一次函数y=ax+b的值为0时,求相应自变量的值．从图象上看,相当于已知直线y=ax+b,确定它与x轴的交点的横坐标的值． [Knowledge points analysis] The relationship between the primary function and the one-dimensional first-order equation The general part of a one-dimensional first-order equation can be transformed into the form of ax+b=0 (a and b are constants, a≠0), so the solution of a one-dimensional equation can be converted into: When the value of the first function y=ax+b is 0, find the value of the corresponding argument. From the image point of view, it is equivalent to the known line y = ax + b, determine the value of the abscissa of its intersection with the x-axis.