Answer:
20
Step-by-step explanation:
6 + 2 = 8
8 + 3 = 11
11 + 4 =15
15 + 5 =20
1. y=7/8x +1
2. y=-10x
3. y=2.5x-7
4. y=1.2x
5. y=-5x-8
The formula for slope is 
In this case:

so...


-1 <<<The slope
Hope this helped!
~Just a girl in love with Shawn Mendes