Equations/Inequalities
What symbol is used in equations?
The equal sign (=).
What is the formula and what does each letter stand for?
Formula: I=prt
I= interest
p= principal or the amount of money you start with
r= rate
t= time
What are the steps for M.A.D
1. find the mean
2. subtract the mean from each number
3.find the mean of the new numbers
What is the formula and what does each letter stand for?
A=p(1+r)^t
A= account balance
p= principal
r= rate
t= time
What is credit/loan?
Money you borrow from the back or money you owe.
What are all the symbols used in inequalities.
< , > , ≤ , ≥
Find the interest earned:
$4000 for 4 years at 5% annual simple interest
$800
Find the Mean Absolute Deviation (to the nearest tenth):
4,33,58,11,28,64
18.7
Find the interest earned:
$1500 for 22 years at 9% annual compound interest
$8487.90 interest
Solve for r:
7r=7(2r+9)
r = -9
Amy had $550 in her savings account when Lisa opened a savings account with zero dollars.
- Amy deposits $20 into her account each week for x weeks.
- Lisa deposits $40 into her account each week for x weeks.
- The accounts did not earn interest
Which inequality represents this situation when the amount of money in Amy's account was greater than the amount of money in Lisa's account?
40x < 550 + 20x
Sophia invests $12,350 in an account that earns 4.5% annual simple interest. Assuming she makes no additional deposits or withdrawals, how much interest will Sophia earn after 36 months?
$1667.25 in interest
Find the Mean Absolute Deviation:
61,68,63,67,70,62,64
2.9
Derrick wants to calculate the interest he would earn from investing $400 into an account that earns 5.5% annual compound interest for 60months. What formula should he use and what should the formula look like? (plug in the numbers)
A=p(1+r)^t
A= 400(1+.055)^5
What value of x makes this equation true?
-12x-2(x+9)=5(x+4)
x=-2
What value of r is a solution to this equation?
–1=–5(r+5)–11
r=-7
Becky has $50 in a savings account that earns 10% annually. The interest is not compounded. How much interest will she earn in 3 years?
$15.00
Find the mean and mean absolute deviation of the amounts spent.
$9,$14,$27,$32,$18
Mean: 20
Mean Absolute Deviation: 7.6
Julio invests $6100 into an account that earns 5.2% annual compound interest. If Julio makes no additional deposits or withdrawals, how much interest will he earn in 8 years?
$3050.73 in interest
Mike wants to borrow $15,000 for home improvements. He was considering a 5-year loan option represented by A = 15,000(1 + 0.029)^5 or a 3-year loan option represented by A = 15,000(1 + 0.043)^3 where A in both equations represents the total cost of repaying the loan.
Which loan option with Mike repay the least amount of money?
The 3 year loan. ($1701.94)
Solve the inequality:
w≤-3.3
Find the interest and account balance:
$21000 for 108 months at an 8.8% annual simple interest rate
Interest - $16632.00
Account Balance - $37632.00
Find the mean and mean absolute deviation for the points scored below.
32,39,31,35,35,40,33
Mean: 35
Mean Absolute Deviation: 2.6
Emma and Paul each invest $2,000 into accounts that warn 6% interest. If Emma's account earns simple interest and Paul's account earns compound interest, what is the values of each person's account after 8 years?
Emma -$2,960
Paul - $3,187.70
Daniel's computer broke. The repair costs are $500. Because he does not have any money saved, he will have to get a "payday loan" for the computer repair. He researched 10-day payday loans and found that he will owe $10.50 for every $100 he borrows, plus the money he borrows.
How much will Daniel have to pay back, if he takes the 10-day payday loan?
$438.00