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5. find the value of: \\(2^{-3}\\)\ 6. combine the terms: \\(\\dfrac{x^…

Question

  1. find the value of: \\(2^{-3}\\)\
  2. combine the terms: \\(\dfrac{x^7 \times x^2}{x^5}\\) (1 mark)\
  3. combining the terms: \\(\dfrac{(b^3)^4}{b^2 \times b^7}\\) (2 marks)\
  4. combine the terms: \\(\dfrac{6^2 \times 2^3}{4^2}\\)\
  5. convert the following ordinary number into standard form: 56,000 (1 mark)\
  6. convert the following decimal into standard form: 0.0000081\
  7. write the following as an ordinary number: \\(4.2 \times 10^6\\) (1 mark)\
  8. write the following as an ordinary number: \\(7.9 \times 10^{-4}\\) (1 mark)\
  9. which is larger? \\(6.3 \times 10^3\\) or \\(1.2 \times 10^6\\) (1 mark)

Explanation:

Response
Question 5: Find the value of \(2^{-3}\)

Step 1: Recall the negative exponent rule

The rule for negative exponents is \(a^{-n}=\frac{1}{a^{n}}\) (where \(a
eq0\) and \(n\) is a positive integer). For \(a = 2\) and \(n=3\), we have \(2^{-3}=\frac{1}{2^{3}}\).

Step 2: Calculate \(2^{3}\)

We know that \(2^{3}=2\times2\times2 = 8\).

Step 3: Substitute back

Substituting \(2^{3}=8\) into \(\frac{1}{2^{3}}\), we get \(\frac{1}{8}=0.125\).

Step 1: Use the product rule of exponents in the numerator

The product rule of exponents states that \(a^{m}\times a^{n}=a^{m + n}\). For \(a=x\), \(m = 7\) and \(n = 2\), we have \(x^{7}\times x^{2}=x^{7 + 2}=x^{9}\). So the expression becomes \(\frac{x^{9}}{x^{5}}\).

Step 2: Use the quotient rule of exponents

The quotient rule of exponents states that \(\frac{a^{m}}{a^{n}}=a^{m - n}\) (where \(a
eq0\)). For \(a=x\), \(m = 9\) and \(n = 5\), we have \(\frac{x^{9}}{x^{5}}=x^{9-5}=x^{4}\).

Step 1: Use the power of a power rule in the numerator

The power of a power rule states that \((a^{m})^{n}=a^{m\times n}\). For \(a = b\), \(m = 3\) and \(n = 4\), we have \((b^{3})^{4}=b^{3\times4}=b^{12}\).

Step 2: Use the product rule of exponents in the denominator

Using \(a^{m}\times a^{n}=a^{m + n}\) with \(a = b\), \(m = 2\) and \(n = 7\), we get \(b^{2}\times b^{7}=b^{2 + 7}=b^{9}\). So the expression becomes \(\frac{b^{12}}{b^{9}}\).

Step 3: Use the quotient rule of exponents

Using \(\frac{a^{m}}{a^{n}}=a^{m - n}\) with \(a = b\), \(m = 12\) and \(n = 9\), we have \(\frac{b^{12}}{b^{9}}=b^{12-9}=b^{3}\).

Answer:

\(\frac{1}{8}\) (or \(0.125\))

Question 6: Combine the terms \(\frac{x^{7}\times x^{2}}{x^{5}}\)