I am not sure but I would say either step 2 or 4 but I am not 100% sure I hope you do well. Good Luck:)
Answer:
15
Step-by-step explanation:

Cross multiply to get 25x = 375
Divide each side by 25 to get x = 15
If "a" and "b" are two values of x-coordinate, and "m" is the midpoint between them, it means the distance from one end to the midpoint is the same as the distance from the midpoint to the other end
... a-m = m-b
When we add m+b to this equation, we get
... a+b = 2m
Solving for m gives
... m = (a+b)/2
This applies to y-coordinates as well. So ...
... The midpoint between (x1, y1) and (x2, y2) is ((x1+x2)/2, (y1+y2)/2)
_____
Jennifer had (x1, y1) = (-4, 10) and (x2, y2) = (-2, 6). So her calculation would be
... midpoint = ((-4-2)/2, (10+6)/2) = (-6/2, 16/2) = (-3, 8)
Brandon had (x1, y1) = (9, -4) and (x2, y2) = (-12, 8). So his calculation would be
... midpoint = ((9-12)/2, (-4+8)/2) = (-3/2, 4/2) = (-1.5, 2)
Answer:
Substitution property of equality
Step-by-step explanation:
Given
and 
Then

Required
State the property
From the list of options, (d) answers the question.
This is so because:
Substitution property of equality states that
If
then 
In other words, both can replace one another.
So if
, then 2y + 1 can be substituted for x in
So:
becomes

<em>Hence, it is substitution property of equality</em>