David purchased some cookies at the cost of 5 for $4 and sold them at 4 for $5. david made a profit of $180 in total. how many cookies did david purchase to make that much money?

David purchased some cookies at the cost of

5 for $4 (5/4=1.25) and

sold them at 4 for $5(4/5=0.80).

To find cost per cookie subtract 1.25-0.80=0.45

David made a profit of $180 in total ( divide profit per cookie cost: 180/0.45= 400)

How many cookies did David purchase to make that much money?

He needed to make 400 cookie to make the profit of $180.

given that triangle abc is transformed two times to get triangle

a"b"c"

first abc is transformed in to a'b'c' as follows:

the coordinates of a are (1,-1) and transformed into a'(-1,1)

similarly b (4,-2) became b'(-4,2) and

c(7,-2) became c'(-7,2)

i.e. (x,y) becomes (-x,-y)

this is nothing but reflection about a point here origin.

thus first transformation is reflection on the origin.

next is exactly shifting 3 units down

source:

the entire expression should be subtracted from 30. to subtract the quantity, distribute the negative sign, which changes the signs on the terms. so, the –2 changes to positive and gets added to 30 instead of subtracted from it.

hope this ! ^w^