Write an equation that represents the following transformation. f(x)=|x| ; vertical stretch by a factor of 3 followed by a translation 7 units down.

Pls help asap

For example, if a function increases three times as fast as its parent function, it has a stretch factor of 3. To find the vertical stretch of a graph, create a function based on its transformation from the parent function, plug in an (x, y) pair from the graph and solve for the value A of the stretch

area of part 1:

a1=base*height/2=(8+2)*(8-2-2-1)/2=10*3/2=15 ft^2

area of part 2:

a2=length*width=(8+2)*1=10 ft2

area of part 3:

a3=length*width=8*2=16 ft2

total shaded area : a1+a2+a3=41 ft2

total area of the reactangle : a=16*8=128 ft2

total area of the nonshaded region : 128-41=87 ft2