Question

函数y1=k1x+b1与y2=k2x+b2满足b1＜b2，且k1×k2＜0的两直线的图像为（）

https://gss0.baidu.com/7LsWdDW5_xN3otqbppnN2DJv/%B2%D0%B4%E6%B5%C4%BC%C7%D2%E4%D8%BC/abpic/item/3d00ccc7890dec18b319a8a2.jpg

https://gss0.baidu.com/7LsWdDW5_xN3otqbppnN2DJv/%B2%D0%B4%E6%B5%C4%BC%C7%D2%E4%D8%BC/abpic/item/5ffcb2cc16ba2f5a7f3e6fa1.jpg

https://gss0.baidu.com/7LsWdDW5_xN3otqbppnN2DJv/%B2%D0%B4%E6%B5%C4%BC%C7%D2%E4%D8%BC/abpic/item/b1c269d57ee4149e572c84a2.jpg

https://gss0.baidu.com/7LsWdDW5_xN3otqbppnN2DJv/%B2%D0%B4%E6%B5%C4%BC%C7%D2%E4%D8%BC/abpic/item/5a64fb264433eabed7cae2a2.jpg

Answer 1

b1<b2
则y1和y轴交点在y2的下方
且k1k2<0则一个向上倾斜，一个向下倾斜
所以选最后一个

Answer 2

5x-1/6=1/2
5x=1/2+1/6
5x=2/3
x=2/3÷5
x=2/15查表或者计算器
=lg99999/lg5约等于7.153447852145821534152123