// Numbas version: exam_results_page_options {"name": "Laws of Indices [L6] Randomised", "extensions": [], "custom_part_types": [], "resources": [["question-resources/Capture_Bk8bYnv.PNG", "/srv/numbas/media/question-resources/Capture_Bk8bYnv.PNG"]], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"extensions": [], "name": "Laws of Indices [L6] Randomised", "statement": "

Using the laws of indices, simplify each expression down to its simplest form.

Recall that $a^{0} = 1$ for any number = $a$.

The ^ symbol is required to write powers of algebraic symbols and * between integers and algebraic symbols, e.g. $5a^2$ should be written 5*a^2.

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This question aims to test understanding and ability to use the laws of indices.

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a)

Here we are using the rule of indices: $a^m \\times a^n = a^{m+n}$.

Using this rule,

\\[
\\begin{align}
a^\\var{x} \\times a^\\var{y}\\ &= a^\\simplify[all, !collectNumbers]{{x}+{y}}\\\\
&= a^\\var{x+y}.
\\end{align}
\\]

b)

We are asked to find $\\var{c}a^\\var{p} \\times \\var{d}a^\\var{q}$.

Notice there is a constant in front of each of the terms.

To do this, write the product out explicitly, as

\\[\\var{c}a^\\var{p} \\times \\var{d}a^\\var{q} = \\var{c} \\times \\var{d} \\times a^\\var{p} \\times a^\\var{q}.\\]

We know that $\\var{c} \\times \\var{d} = \\var{c*d}$, and using the rule of indices: $a^\\var{p} \\times a^\\var{q} = a^\\var{p+q}$.

Therefore:

\\begin{align}
\\var{c}a^\\var{p} \\times \\var{d}a^\\var{q}&= \\var{c*d} \\times a^\\var{p+q} \\\\
&= \\simplify{{c*d}*a^{p+q}}.
\\end{align}

c)

Here we are using: $a^m \\div a^n = a^{m-n}$.

We are asked to simplify the expression, $\\displaystyle\\simplify{{b}*a^{x}/({g}*a^{y})}$.

To do this, we just have to use the previously mentioned rule of indices. We write this out explicity as

\\[\\simplify{{b}*a^{x}/({g}*a^{y})} = \\simplify{{b}/{g}} \\times \\simplify{a^{x}/(a^{y})}.\\]

Using rules of indices,

\\begin{align} \\frac{a^\\var{x}}{a^\\var{y}} &= a^\\var{x} \\div a^\\var{y}\\\\
&= a^\\simplify[all, !collectNumbers]{{x}-{y}}\\\\
&= a^\\var{x-y}.
\\end{align}

Therefore,

\\begin{align}
\\frac{\\var{b}a^\\var{x}}{\\var{g}a^\\var{y}} &= \\simplify{{b}/{g}} \\times \\simplify{a^{{x}-{y}}}\\\\
&= \\simplify{{b}/{g}*a^{x-y}}.
\\end{align}

Alternatively,

Using the rule of indices: $a^{-m} = \\displaystyle\\frac{1}{a^{m}}$, we can rewrite the question as:

\\begin{align}
\\frac{\\var{b}a^\\var{x}}{\\var{g}a^\\var{y}} &= \\simplify{{b}/{g}} \\times \\frac{a^\\var{x}}{a^\\var{y}}\\\\
&= \\simplify{{b}/{g}} \\times a^\\var{x} \\times a^{-\\var{y}}.
\\end{align}

And then using the rule: $a^m \\times a^n = a^{m+n}$, this becomes:

\\begin{align}
\\simplify{{b}/{g}} \\times a^\\var{x} \\times a^{-\\var{y}} &= \\simplify{{b}/{g}} \\times a^\\simplify[all,!collectNumbers]{{x}+(-{y})}\\\\
&= \\simplify{{b}/{g}*a^{x-y}}.
\\end{align}

d)

The question asks us to simplify $(\\simplify{{c}*a^{p}})^{\\var{q}}$.

To do this we use the rules:

\\[(a^{m})^{n} = a^{mn},\\]

\\[(ab)^m = a^mb^m.\\]

We can then expand the equation as

\\[(\\simplify{{c}*a^{p}})^{\\var{q}}= \\var{c}^{\\var{q}} \\times (a^{\\var{p}})^{\\var{q}}.\\]

Then using the rule of indices mentioned previously,

\\[
\\begin{align}
(\\simplify{{c}*a^{p}})^{\\var{q}}&= \\simplify{{c}^{q}} \\times a^\\var{p*q}\\\\
&= \\simplify{{c}^{q}*a^{p*q}}.
\\end{align}
\\]

e)

The question asks us to simplify $\\sqrt[\\var{d}]{\\var{x}^\\var{d}a}$.

To do this we use the rules:

\\[a^\\frac{1}{m} = \\sqrt[m]{a},\\]

\\[(ab)^m = a^mb^m.\\]

We can expand the expression as follows:

\\[
\\begin{align}
\\sqrt[\\var{d}]{a} &= (\\simplify{a})^\\frac{1}{\\var{d}}\\\\
&= a^\\frac{1}{\\var{d}}.
\\end{align}
\\]

f)

The question requires us to simplify $\\sqrt[\\var{c}]{a^\\var{q}}$.

Here, we use the rule of indices: $a^\\frac{n}{m} = \\sqrt[m]{a^n}$, allowing us to expand the expression as follows:

\\[
\\begin{align}
\\sqrt[\\var{c}]{\\simplify{a^{q}}} &= \\simplify[fractionnumbers,all]{(a^{q})^{{1}/{{c}}}}\\\\
&= \\simplify[fractionnumbers,all]{a^{{q}/{c}}}.
\\end{align}
\\]

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Use the rule: $a^m \\times a^n = a^{m+n}$.

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Write $a^{\\var{x}} \\times a^{\\var{y}}$ as a single power of $a$.

$a^{\\var{x}} \\times a^{\\var{y}} =$ [[0]].

You must write your answer as a single power of a.

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Write $\\var{c}a^\\var{p} \\times \\var{d}a^\\var{q}$ as an integer multiplied by a single power of $a$.

$\\var{c}a^\\var{p} \\times \\var{d}a^\\var{q} =$ [[0]].

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You could use one of the following rules:

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$a^{-m} = \\displaystyle\\frac{1}{a^m}$.

Write $\\displaystyle\\simplify{{b}*a^{x}/({g}*a^{y})}$ as a number multiplied by a single power of $a$.

$\\displaystyle\\simplify{{b}*a^{x}/({g}*a^{y})} =$ [[0]].

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Use the rules:

$(ab)^m = a^mb^m$.

$(a^m)^n = a^{mn}$.

Write $(\\simplify{{c}*a^{p}})^{\\var{q}}$ as an integer multiplied by a single power of $a$.

$(\\simplify{{c}*a^{p}})^{\\var{q}} =$ [[0]].

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You must enter your answer as an integer multiplied by a single power of a.

Use the rule: $a^\\frac{1}{m} = \\sqrt[m]{a}$.

Write $\\sqrt[\\var{d}]{a}$ as a single power of $a$.

$\\sqrt[\\var{d}]{a} =$ [[0]].

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Write $\\sqrt[\\var{q}]{a^\\var{c}}$ as a single power of $a$.

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Used in parts b and d

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