For the equation 27x = 3x+7, which of the following is the solution for x?

  1. No solution
    Incorrect. You may consider getting the same base first.
  2. x = 3.5
    Correct! You solved the equations correctly.
  3. x = 7 4
    Incorrect. After setting exponents equal, subtract x from both sides to isolate variable.
  4. x = 2
    Incorrect. Check solution.

Suzanne wants to solve the equation below by finding the same bases.

42x = 8x-1

Which of the following could be the first step to solve this equation using the same bases?

  1. 22x+2 = 2x-1+2
    Incorrect. When raising a power to a power, multiply the exponents.
  2. 84x = 8x-1

    Incorrect. 42 ≠ 82

  3. 42x = 42(x-1)
    Incorrect. 42 ≠ 8
  4. 24x = 23(x-1)
    Correct! You substituted 22 for 4 and 23 for 8.

Roy needs help solving the equation below. He did the first step and then got stuck.

721 = 23x
log721 = log23x

Which of the following is the next step to solve the equation?

  1. log 721 = (3x)log 2
    Correct! Since there was a power raised to a higher power, you multiplied.
  2. log 721 = 21log 3x
    Incorrect. For a power to a power, multiply. This one transposed the numbers.
  3. (3x)log 721 = log 2
    Incorrect. For a power to a power, multiply. This one multiplied 3x to the other side.
  4. (2)log 721= log 3x
    Incorrect. For a power to a power, multiply. This one transposed the numbers and multiplied to wrong side.

For the equation 20,000 = 10,000(1.045)t, which of the following is a solution for t?

  1. t = 1.1
    Incorrect. Isolate the exponential term first.
  2. t = 15.7
    Correct! You solved correctly.
  3. t = 0.06
    Incorrect. To isolate variable, divide by coefficient.
  4. t = 0.01
    Incorrect. To isolate variable, divide by coefficient.