- Slope-Intercept Form: y = mx + b, with m = slope and b = y-intercept.
If two lines are perpendicular, then they will have slopes that are negative reciprocals to each other. An example of negative reciprocals are 2 and -1/2
6.
Now with line 2, I have to convert it to slope intercept form. Firstly, subtract 2x on both sides of the equation:
![-5y=-2x+8](https://img.qammunity.org/2019/formulas/mathematics/middle-school/ukrhaqrj31wa5lowes558zv882bo91gdp1.png)
Next, divide both sides by -5 and your slope-intercept form is
![y=(2)/(5)x+(8)/(5)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/t6hf9ykcy7mt9pifx2dsb9ku2ny3el3w2w.png)
Now since 2/5 is not the negative reciprocal of -2/5, these lines are not perpendicular.
7.
It's pretty much the same process; convert to slope-intercept and determine if negative reciprocal. This time I'll brush through them:
![6x-3y=15 \\-3y=-6x+15\\y=2x-5\\\\2x+4y=-12\\4y=-2x-12\\y=-(1)/(2)x-3](https://img.qammunity.org/2019/formulas/mathematics/middle-school/8xs6n56ryex41xytjqeqbbygqv9yrmbg8y.png)
Now since 2 is the negative reciprocal of -1/2, these lines are perpendicular.