Acoin contains
1
.
2
5
1.251, point, 25 grams of nickel and
3
.
7
5
3.753, point, 75 grams of copper, for a total weight of
5
55 grams.
what percentage of the metal in the coin is copper?

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: