Answer:
The solution is:
Step-by-step explanation:
Given the expression

Solving


so



∵ 
Therefore, the solution is:

Plan A gives you 6% interest compounded annually so after 4 years
$2000 becomes $2000*(1.06)^4 = $2524.95
Plan B gives you 13% annual simple interest so after 4 years
$2000 becomes $2000*(1+0.13*4) = $3040
so Plan B earns more
She can make 12 different combinations.
If she used three different colors for the keychain, there's still 4 other colors left.
4 x 3 = 12
Angle α and β are supplementary angles and when added together equal 180.
Set up an equation:
α + β = 180
β = α +30
Replace β in the first equation, to get:
α + α +30 = 180
Simplify:
2α +30 = 180
Subtract 30 from both sides:
2α = 150
Divide both sides by 2:
α = 150 /2
α = 75 degrees.