First, you must use a factor tree to find the prime factors of the number.
12
/ \
6 (2)
/ \
(3) (2)
2 , 2 and 3 are the prime factors that make 12
2 x 2 x 3= 12
Or
2^2 x 3= 12
The complete question in the attached figure
we know that
length side AB=8 units
length side DE=4 units
[ABC]=[DEF]*[scale factor]
then
[scale factor ]=[ABC]/[DEF]---------> 8/4--------> 2
the answer is
the scale factor for a dilation image of DEF to obtain ABC is 2
well, the subtotal or pre-tax bill is $23.50, now let's add the 8% tax and

so the post-tax bill is 23.50 + 1.88 = 25.38, and Jackie's tip is 20% of that
