High School

4. \((16)^{0.16} \times (16)^{0.04} \times (2)^{0.2}\) is equal to:

(a) 1
(b) 2
(c) 4
(d) 16

5. If \(\left(\frac{4}{11}\right)^{x-1} = \left(\frac{11}{4}\right)^{x-5}\), then \(x\) is equal to:

(a) 3
(b) 0
(c) -1
(d) 2

6. What is the area of a rectangle with length \(3^3\) metres and width \(9^{-2}\) metres?

(a) \(\frac{1}{9}\) square metres
(b) 3 square metres
(c) \(\frac{1}{3}\) square metres
(d) \(\frac{1}{27}\) square metres

Answer :

Let's solve each part of the problem step by step.

  1. Expression: [tex](16)^{0.16} \times (16)^{0.04} \times (2)^{0.2}[/tex]

    We can simplify this expression using the laws of exponents:

    • The law of exponents states that [tex]a^m \times a^n = a^{m+n}[/tex]. So, we can combine the first two terms:

      [tex](16)^{0.16} \times (16)^{0.04} = (16)^{0.16 + 0.04} = (16)^{0.20}[/tex]

    • Since $16 = 2^4[tex], we can rewrite[/tex](16)^{0.20}$ as:

      [tex](2^4)^{0.20} = 2^{4 \times 0.20} = 2^{0.80}[/tex]

    • Now we multiply by [tex](2)^{0.2}[/tex]:

      [tex]2^{0.80} \times 2^{0.2} = 2^{0.80 + 0.2} = 2^{1.0} = 2[/tex]

    Thus, the expression evaluates to 2.

    Answer for Part 1: The expression is equal to (b) 2.

  2. Equation: [tex]\left(\frac{4}{11}\right)^{x-1} = \left(\frac{11}{4}\right)^{x-5}[/tex]

    Let's solve for [tex]x[/tex].

    • We can rewrite the right-hand side of the equation as:

      [tex]\left(\frac{4}{11}\right)^{-(x-5)} = \left(\frac{4}{11}\right)^{-x+5}[/tex]

    • Now the equation becomes:

      [tex]\left(\frac{4}{11}\right)^{x-1} = \left(\frac{4}{11}\right)^{-x+5}[/tex]

    • Since the bases are the same, we equate the exponents:

      [tex]x - 1 = -x + 5[/tex]

    • Solving for [tex]x[/tex], we add [tex]x[/tex] to both sides:

      [tex]x + x - 1 = 5[/tex]

      [tex]2x - 1 = 5[/tex]

    • Now, add 1 to both sides:

      [tex]2x = 6[/tex]

    • Finally, divide both sides by 2:

      [tex]x = 3[/tex]

    Answer for Part 2: [tex]x[/tex] is equal to (a) 3.

  3. Area of the Rectangle:

    • The length of the rectangle is $3^3[tex]metres, and the width is $9^{-2}[/tex] metres.

    • Calculate the dimensions:

      • Length: $3^3 = 27$ metres.
      • Width: $9 = 3^2[tex], so $9^{-2} = (3^2)^{-2} = 3^{-4}[/tex].
    • Now calculate the area using the formula for the area of a rectangle:

      [tex]\text{Area} = \text{Length} \times \text{Width} = 27 \times 3^{-4}[/tex]

    • Convert $3^{-4}$ to a positive exponent:

      [tex]3^{-4} = \frac{1}{3^4} = \frac{1}{81}[/tex]

    • Thus, the area is:

      [tex]27 \times \frac{1}{81} = \frac{27}{81} = \frac{1}{3}[/tex]

    Answer for Part 3: The area of the rectangle is (c) [tex]\frac{1}{3}[/tex] metres.