You can
put this solution on YOUR website!1) You invest $18000 at 6% interest per year. Set up an exponential equation
and use it to determine how much money you will have after 5 years.
:
A = 18000*(1+.06)^5
A = 18000*1.06^5
A = 18000*1.3382
A = $24,088.06
;
:
2) The chemical element strontium has a half-life of 25 years.
If 8g were present initially, how long will it take for the amount to be
reduced to 2g? Set up an exponential equation and solve algebraically.
:
t = time in yrs for this to happen
= 2
divide both sides by 8
=
= .25
Using nat logs
*ln(2) = ln(.25)
.693*
= -1.386
:
Multiply both sides by 25
-.693t = -1.386 * 25
:
-.693t = -34.657
t =
t = +50.0 yrs
:
:
3) Solve for x: 3^(4x-1)= 9^1/3
Cube both sides and you have;
therefore
12x - 3 = 2
12x = 2 + 3
x =
:
:
you can check all three solutions by substitution and entering the
original equations into a good calc
