A half-life of 9 minutes corresponds to a decay factor <em>k</em> such that

Then the time it takes for the substance to decay from 610 g to 124 g is time <em>t </em>such that

Solve for <em>t</em> :



so it takes about 20.7 min for the 610 g sample to decay down to 124 g.
The given figure can be divided in two parts 1) Square with side 7 in 2) A right triangle with base 12 in and height 7 in.
1) Area of square = 
Side of the square is 7 in.
Area = 
2) Area of triangle = 
Area of triangle =
Area of polygon= Area of square+ Area of triangle
Area of polygon = 49+42 =91 square in.
Area = 
you take 38 hours and multipy it by 10.50 is $399.00
Two hundred and ninety hope i helped
Max height is the vertex
convert to vertex form (y=a(x-h)^2+k) by completeing the square
h(t)=-16(t²-4t)+80
h(t)=-16(t²-4t+4-4)+80
h(t)=-16((t-2)²-4)+80
h(t)=-16(t-2)²+64+80
h(t)=-16(t-2)²+144
vertex is (2,144)
at t=2, the height is 144
max height is 144ft