"

Answer Key 11.4

[latexpage]

  1. \(\begin{array}{rrrrrrrr}
    \\ \\
    &1&-&2n&=&1&-&3n \\
    -&1&+&3n&&-1&+&3n \\
    \midrule
    &&&n&=&0&&
    \end{array}\)
  2. \(\begin{array}{rrl}
    \\ \\ \\ \\ \\
    4^{2x}&=&4^{-2} \\ \\
    \dfrac{2x}{2}&=&\dfrac{-2}{2} \\ \\
    x&=&-1
    \end{array}\)
  3. \(\begin{array}{rrl}
    \\ \\
    4^{2a}&=&4^0 \\
    2a&=&0 \\
    a&=&0
    \end{array}\)
  4. \(\begin{array}{rrl}
    \\ \\ \\ \\ \\ \\
    (4^2)^{-3p}&=&(4^3)^{3p} \\
    4^{-6p}&=&4^{9p} \\
    -6p&=&\phantom{+}9p \\
    +6p&&+6p \\
    \midrule
    0&=&15p \\ \\
    p&=&0
    \end{array}\)
  5. \(\begin{array}{rrl}
    \\ \\ \\ \\ \\ \\ \\
    (5^{-2})^{-k}&=&(5^3)^{-2k-2} \\
    5^{2k}&=&5^{-6k-6} \\
    2k&=&-6k-6 \\
    +6k&&+6k \\
    \midrule
    8k&=&-6 \\ \\
    k&=&-\dfrac{6}{8}\Rightarrow -\dfrac{3}{4}
    \end{array}\)
  6. \(\begin{array}{rrl}
    \\ \\ \\ \\ \\ \\ \\
    (5^4)^{-n-2}&=&5^{-3} \\
    5^{-4n+8}&=&5^3 \\
    -4n+8&=&\phantom{-}3 \\
    -8&&-8 \\
    \midrule
    -4n&=&-5 \\ \\
    n&=&\dfrac{5}{4}
    \end{array}\)
  7. \(\begin{array}{rrl}
    \\ \\ \\ \\ \\ \\
    6^{2m+1}&=&6^{-2} \\
    2m+1&=&-2 \\
    -1&&-1 \\
    \midrule
    2m&=&-3 \\ \\
    m&=&-\dfrac{3}{2}
    \end{array}\)
  8. \(\begin{array}{rrl}
    \\ \\
    2r-3&=&\phantom{-}r-3 \\
    -r+3&&-r+3 \\
    \midrule
    r&=&0
    \end{array}\)
  9. \(\begin{array}{rrl}
    \\ \\ \\
    6^{-3x}&=&6^2 \\
    \therefore -3x&=&2 \\
    x&=&-\dfrac{2}{3}
    \end{array}\)
  10. \(\begin{array}{rrl}
    \\ \\ \\ \\
    2n&=&-n \\
    +n&&+n \\
    \midrule
    3n&=&0 \\ \\
    n&=&0
    \end{array}\)
  11. \(\begin{array}{rrl}
    \\ \\ \\
    (2^6)^b&=&2^5 \\
    6b&=&5 \\ \\
    b&=&\dfrac{5}{6}
    \end{array}\)
  12. \(\begin{array}{rrl}
    \\ \\ \\ \\ \\ \\
    (6^3)^{-3v}&=&(6^2)^{3v} \\
    6^{-9v}&=&6^{6v} \\
    -9v&=&6v \\
    +9v&&+9v \\
    \midrule
    0&=&15v \\ \\
    v&=&0
    \end{array}\)
  13. \(\begin{array}{rrl}
    \\ \\ \\
    (4^{-1})^x&=&4^2 \\
    4^{-x}&=&4^2 \\
    \therefore -x&=&2 \\
    x&=&-2
    \end{array}\)
  14. \(\begin{array}{rrl}
    \\ \\ \\ \\ \\ \\ \\
    (3^3)^{-2n-1}&=&3^2 \\
    3^{-6n-3}&=&3^2 \\
    -6n-3&=&2 \\
    +3&=&+3 \\
    \midrule
    -6n&=&5 \\ \\
    n&=&-\dfrac{5}{6}
    \end{array}\)
  15. \(\begin{array}{rrl}
    \\
    \therefore 3a&=&3 \\
    a&=&1
    \end{array}\)
  16. \(\begin{array}{rrl}
    \\ \\
    4^{-3v}&=&4^3 \\
    \therefore -3v&=&3 \\
    v&=&-1
    \end{array}\)
  17. \(\begin{array}{rrl}
    \\ \\ \\ \\
    (6^2)^{3x}&=&\phantom{-}(6^3)^{2x+1} \\
    6^{6x}&=&\phantom{-}6^{6x+3} \\
    \therefore 6x&=&\phantom{-}6x+3 \\
    -6x&&-6x \\
    \midrule
    0&=&3 \Rightarrow \text{no solution}
    \end{array}\)
  18. \(\begin{array}{rrl}
    \\ \\ \\ \\ \\ \\ \\
    (4^3)^{x+2}&=&4^2 \\
    4^{3x+6}&=&4^2 \\
    \therefore 3x+6 & =&\phantom{-}2 \\
    -6&&-6 \\
    \midrule
    3x&=&-4 \\ \\
    x&=&-\dfrac{4}{3}
    \end{array}\)
  19. \(\begin{array}{rrl}
    \\ \\ \\ \\ \\ \\ \\
    (3^2)^{2n+3}&=&3^5 \\
    3^{4n+6}&=&3^5 \\
    \therefore 4n+6&=&\phantom{-}5 \\
    -6&&-6 \\
    \midrule
    4n&=&-1 \\ \\
    n&=&-\dfrac{1}{4}
    \end{array}\)
  20. \(\begin{array}{rrl}
    \\ \\ \\ \\
    (4^2)^{2k}&=&4^{-3} \\
    4^{4k}&=&4^{-3} \\
    \therefore 4k&=&-3 \\ \\
    k&=&-\dfrac{3}{4}
    \end{array}\)
  21. \(\begin{array}{rrl}
    \\ \\
    3x-2&=&\phantom{-}3x+1 \\
    -3x+2&&-3x+2 \\
    \midrule
    0&=&\phantom{-}3\Rightarrow \text{no solution}
    \end{array}\)
  22. \(\begin{array}{rrl}
    \\ \\ \\ \\ \\
    (2^5)^p&=&(3^2)^{-3p} \\
    \therefore 5p&=&-6p \\
    +6p&&+6p \\
    \midrule
    11p&=&0 \\ \\
    p&=&0
    \end{array}\)
  23. \(\begin{array}{rrl}
    \\ \\
    -2x&=&3 \\
    x&=&-\dfrac{3}{2}
    \end{array}\)
  24. \(\begin{array}{rrl}
    \\ \\ \\ \\ \\
    2n&=&2-3n \\
    +3n&&\phantom{2}+3n \\
    \midrule
    5n&=&2 \\ \\
    n&=&\dfrac{2}{5}
    \end{array}\)
  25. \(\begin{array}{rrl}
    \\ \\ \\ \\
    m+2&=&-m \\
    +m-2&=&+m-2 \\
    \midrule
    2m&=&-2 \\ \\
    m&=&-1
    \end{array}\)
  26. \(\begin{array}{rrl}
    \\ \\ \\ \\
    (5^4)^{2x}&=&5^2 \\
    5^{8x}&=&5^2 \\
    \therefore 8x&=&2 \\ \\
    x&=&\dfrac{1}{4}
    \end{array}\)
  27. \(\begin{array}{rrl}
    \\ \\ \\ \\ \\ \\ \\
    (6^{-2})^{b-1}&=&6^3 \\
    6^{-2b+2}&=&6^3 \\
    \therefore -2b+2&=&\phantom{-}3 \\
    -2&& -2 \\
    \midrule
    -2b&=&\phantom{-}1 \\ \\
    b&=&-\dfrac{1}{2}
    \end{array}\)
  28. \(\begin{array}{rrl}
    \\ \\ \\ \\
    (6^3)^{2n}&=&6^2 \\
    6^{6n}&=&6^2 \\
    \therefore 6n&=&2 \\ \\
    n&=&\dfrac{1}{3}
    \end{array}\)
  29. \(\begin{array}{rrl}
    \\ \\ \\ \\
    2-2x&=&\phantom{-}2 \\
    -2\phantom{-2x}&=&-2 \\
    \midrule
    -2x&=&0 \\ \\
    x&=&0
    \end{array}\)
  30. \(\begin{array}{rrl}
    \\ \\ \\ \\
    (2^{-2})^{3v-2}&=&\phantom{-}(2^6)^{1-v} \\
    2^{-6v+4}&=&\phantom{-}2^{6-6v} \\
    \therefore -6v+4&=&\phantom{-}6-6v \\
    +6v-4&& -4+6v \\
    \midrule
    0&=&\phantom{-}2\Rightarrow \text{No solution}
    \end{array}\)

License

Icon for the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License

Intermediate Algebra Copyright © 2020 by Terrance Berg is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, except where otherwise noted.