9.333048
is what I believe the mystery number would be
Answer:
Midpoint = (3.5, 4.5)
Perpendicular bisector = y =
x + 
Step-by-step explanation:
[] We can solve this using the midpoint formula:
-> See attached
[] Plug-in our coordinates and solve:

[] Now we will find the slope to solve for the perpendicular bisector.
-> We will use slope-intercept form, see attached

-> The slopes of two perpendicular lines are negative reciprocals of each other, so
will be the slope of or perpendicular bisector
-> Now we can solve for the equation by using y – y1 = m ( x – x1), were y1 and x1 are the coordinates of our midpoint
y - 4.5 =
(x-3.5)
y - 4.5 =
x-
y =
x-
+ 4.5
y =
x + 
Have a nice day!
I hope this is what you are looking for, but if not - comment! I will edit and update my answer accordingly. (ノ^∇^)
- Heather
Answer:
3x-2y=17........(1)
x=4y-1
substituting value of x in equation 1
3(4y-1)-2y=17
12y-3-2y=17
10y=17+3
y=20/10=2
again
substituting value of y in equation 1
3x-2×2=17
3x=17+4
x=21/3=7
:.x=7,y=2
First, you must change all of this into improper fractions, like shown below.

Now you must change the sign.

Then we must reciprocalize 2/3.

Now we multiply, to get 2 4/10.
Its 3.8 because if you add 5.9 and 10.3 is 16.2, and if you subtract it by 20, it should equal 3.8.