21 = 4x - 9 - x
what is x?

x = 10

Step-by-step explanation:

21 = 4x - 9 - x

21 = 3x - 9

30 = 3x

10 = x

x = 10

Step-by-step explanation:

Given

21 = 4x - 9 - x, that is

21 = 3x - 9 ( add 9 to both sides )

30 = 3x ( divide both sides by 3 )

10 = x

step-by-step explanation:

given that ab is divided into equal parts as

ac, cd, de, ef, fg, gh, hi, ib.

from this we find that f is the midpoint of ab.

so using mid point formula we find

f = (3,7)

similarly considering fb, we get

h = mid point of fb = ((6,6) and g, mid point of fh is

g = (9/2, 13/2)

i is mid point of hb

so i =(15/2,11/2)