How is -9 + (-4) the same as -9 + 4?

-9 - (-4) is the same as -9 + 4 because subtracting a negative is the same as addition. I'm not quite sure how to represent it with the integer chip model, but basically, taking away -4 from -9 is the same as adding positive 4 to -9.

Perhaps draw the 9 negative chips and place the four negative chips under it, then cross out those that correspond to show that it is increasing in sum?

answer: 72: 111

step-by-step explanation:

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)