Answer:
The first one is proportional and the second one is not. Because for the first one you can see that if you divide the number of pens by the cost you'll get the same answer for every single one. But for the second one if you divide the number of minutes by words typed you get a different answer for each one. You can also see if it's proportional or not if you draw it on the graph and it's a straight line. If it is the relationship is proportional if it isn't it's not proportional. Hope that makes sense :)
Use the formula slope= y-y/x-x
-10-r/-2-8= 1/10
-10-r/-10= 1/10
Multiply the denominator (-10) on both sides
-10-r= -1
Add -10 to both sides
-r= 9
r= -9
Hope this helps!
The quadratic formula is
.
From the problem, a is 1, b is -1, and c is 12. Plugging in these values gives:

Because there is a square root of a negative number, there is no solution.
Answer:
k = -8
Step-by-step explanation:
The location of P is ...
P = (2A+B)/3 = (2·2+5, 2·1-8)/3 = (3, -2)
Putting this point into the equation for the line, we have ...
2(3) -(-2) +k = 0
8 +k = 0
k = -8