Elena is thinking about putting $200 in a savings account that earns 4% interest compounded semiannually. she wants to keep that money in the account for 4 years. which of the formulas below can her calculate how much money she will have at the end of the 4 years? a. $200(1 + 0.02)8 b. $200(1 + 0.04)4 c. $200(1 + 0.02)4 d. $200(1 + 0.08)2

A.

Step-by-step explanation:

Since, the amount that compounded semiannually is,

Where, P is the principal amount,

r is the annual rate ( in decimals ),

And, t is time ( in years ),

Here, P = $ 200,

r = 4 % = 0.04    ( 1 % = 0.01 ),

t = 4 years,

Hence, the amount after 4 years would be,

⇒ First option is correct.

answer: c.  

step-by-step explanation:

mixtures containing substances that get attracted to magnet can be separated using a magnet. we can separate iron from a mixture of sand and iron, as only iron attracts to the magnet.

see explanation

step-by-step explanation:

a

(6r + 7) + (13 + 7r) ( remove brackets and collect like terms )

= 6r + 7 + 13 + 7r

= 13r + 20

b

remove brackets and collect like terms

13 - r - 1 + r

= 12 - r

c

remove brackets and collect like terms

= - 8 - r + 2r - 4

= - 12 + r

d

remove brackets and collect like terms

= 7r - - - 6r

[-   - = - - = - ]

= r -