What is the slope of the line that passes through the points)(7,−4) and (7, 0) ? Write your answer in simplest form.

Slope=Δy/Δx=(y2-y1)/(x2-x1)

The points are (7,-4) and (7,0)

So slope= [ 0 -( -4 ) ] / [ 7 -7 ] = 4/0 =undefined

We know this is the vertical line of x=7 and vertical lines have undefined (or infinite) slope

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional

you didn't post any answer choices, so its not 100% clear what your teacher is looking for

however, log(15/7) is equivalent to log(15) - log(7)

i'm using the rule log(x/y) = log(x) - log(y)