Hi,
Perimeter AEDCB=3*10+15+20=65 (units)
Ratio of the similitude r*15=21==>r=21/15=1.4
Perimeter RQPTS=65*1.4=91(units)
7) 2-9= -7 because, if you have two cookies and promised nine friends cookies, you would still owe 7 friends cookies or -7
8) -3 - (-4)= 1 because you owe 3 friends cookies, then you get 4 cookies and have one left over
9) 11 - (-12)= 23 because a negative plus a negative is a positive
The Volume of this pyramid is 5040 cm³
Hope this helps
Check the picture below.
something worth noticing 
so, we're really graphing x+2, with a hole at x = 3, however, when x = 3, we know that f(x) = 5, but but but, when x = 3, x+2 = 5, so we end up with a continuous line all the way, x ∈ ℝ, because the "hole" from the first subfunction, gets closed off by the second subfunction in the piece-wise.
Answer:
x=a/(y-k)+h
Step-by-step explanation:
y-k=a/(x-h)
(y-k)(x-h)=a
xy-hy-kx+kh=a
xy-kx=a+hy-hk
x(y-k)=a+h(y-k)
x=a/(y-k)+h