Answer:
X < 9
The hallow circle means just greater than or less than
The numberline is pointing downwards showing that 9 is greater than x(unknown value)
The point is also on 9
Answer:
1) 3( 2) - 1 = 6 - 1 = 5
2) 2(-1) - 3+4(-1) = -2 -7 = -9
3) 4^2-6(4)=9 = 16-24=9, = -8=9
Answer:
a)
, b)
, c)
, d) 
Step-by-step explanation:
a) Let assume an initial mass m decaying at a constant rate k throughout time, the differential equation is:

b) The general solution is found after separating variables and integrating each sides:

Where
is the time constant and 
c) The time constant is:


The particular solution of the differential equation is:

d) The amount of radium after 300 years is:

Answer:
Step-by-step explanation:
Pythagoras theorem
a^2=b^2+c^2
(x-2)^2=9^2+(x+1)^2
x^2-4x+4=81+x^2+2x+1
Collect like terms
-4x-2x=82-4
-6x=78
x=-13