The like terms are all the ones with the same variable/ letter
Answer:
Expression for Perimeter: 6x + 6
x = 12 cm
Verify A = 360:
2(12) x (12+3) = 360
24 x 15 = 360
360 = 360
Step-by-step explanation:
Answer:
The half life of a material is the time that a given quantity A of the material, decays into its half.
We know that the half-life is 4 hours, then we have the equation:
Q(t) = A*r^t
Where A is the initial quantity, and t is the number of hours.
and we have that r^4 = 1/2 (so when t = 4, we will have half of A)
then r = (1/2)^(1/4) = 0.84
Then our relation is
Q(t) = A*0.84^t
We have that A = 225mg,
at 1:00 pm. we have one hour after noon, so here we need to use t = 1.
Q(1) = 225mg*0.84^1 = 189.2mg
At 7:00 pm, we have 7 hours since noon, so here we need to use t = 7
Q(7) = 225mg*0.84^7 = 66.4mg
