SAT Problem Help

[JCoupe]

1) If n and k are positive integers and 8^n = 2^k, what is the value of n/k?

Why does it equal 1/3?
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2) Davids Monthly Expenses
Rent & Utilities - 35%
Food - 25%
Clothing - 5%
Other - 15%
Car - 20%

If David spends $450 per month for food, how much does he spend a month on his car?

Why does it equal $360?
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3) If the function f is defined by f(x) = 3x+4, then 2f(x)+4= 6x+12.

Why?

 

[Denis]

If n and k are positive integers and 8^n = 2^k, what is the value of n/k?
Why does it equal 1/3?

Hint: 8 = 2^3
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Davids Monthly Expenses
Rent & Utilities - 35%
Food - 25%
Clothing - 5%
Other - 15%
Car - 20%

If David spends $450 per month for food, how much does he spend a month on his car? Why does it equal $360?

Hint: if a% = x, then b% = x / a * b
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If the function f is defined by f(x) = 3x+4, then 2f(x)+4= 6x+12. Why?

Hint: you're told to double, then add 4

Next time you post something like this: SHOW YOUR WORK :shock:

 

[stapel]

1) Express 8 as a power of 2, and simplify the expression 8ⁿ. Equate the powers, and solve for n in terms of k. Then evaluate the ratio.

2) If $450 is 25% of his income, what is his total income? What then is 20% of this?

3) Just simplify the given expression: multiply by 2, and then add 4.

Please reply showing your steps and where you are stuck. Please be specific. Thank you.

Eliz.