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multiplying_expressions_1.html
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multiplying_expressions_1.html
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<!DOCTYPE html>
<html data-require="math math-format expressions">
<head>
<meta charset="UTF-8" />
<title>Multiplying expressions 1</title>
<script src="../khan-exercise.js"></script>
<script type="text/javascript">
function mult() {
return jQuery.map( jQuery.makeArray(arguments), function(val, i) {
return KhanUtil.plus(val); // do something
}).join( " \\cdot " );
}
function parens( s ) {
return "\\left( " + KhanUtil.plus(s) + " \\right)";
}
</script>
</head>
<body>
<div class="exercise">
<p class="summary">This exercise covers simplifying expressions of the form
(Ax + B)(Cx + D)</p>
<div class="vars">
<!-- 1/4 of questions will be squares -->
<var id="SQUARE">random() < 0.25</var>
<var id="A">randRangeNonZero( -10, 10 )</var>
<var id="B">randRangeNonZero( -10, 10 )</var>
<var id="C">SQUARE ? A : randRangeNonZero( -10, 10 )</var>
<var id="D">SQUARE ? B : randRangeNonZero( -10, 10 )</var>
<var id="X">"x"</var>
<var id="XX">"x^2"</var>
<var id="LEFT">"\\left(" + plus( A+X, B ) + "\\right)"</var>
<var id="RIGHT">"\\left(" + plus( C+X, D ) + "\\right)"</var>
</div>
<div class="problems">
<div>
<p class="question"><code><var>LEFT + ( SQUARE ? "^2" : RIGHT )</var> = \ ?</code></p>
<p class="solution"><code><var>plus( (A*C)+XX, (A*D+B*C)+X, B*D )</var></code></p>
<ul class="choices" data-show="4" data-none="true">
<li><code><var>plus( (A+C)+XX, (A*D+B*C)+X, B*D )</var></code></li>
<li><code><var>plus( (A*C)+XX, (A*D+B*C)+X, B+D )</var></code></li>
<li><code><var>plus( (A+C)+XX, (A*D+B*C)+X, B+D )</var></code></li>
<li><code><var>plus( (A+C)+XX, (A*D-B*C)+X, B*D )</var></code></li>
<li><code><var>plus( (A*C)+XX, (A*D-B*C)+X, B+D )</var></code></li>
<li><code><var>plus( (A+C)+XX, (A*D-B*C)+X, B+D )</var></code></li>
<li><code><var>plus( (A+C)+XX, (A*B+C*D)+X, B*D )</var></code></li>
<li><code><var>plus( (A*C)+XX, (A*B+C*D)+X, B+D )</var></code></li>
<li><code><var>plus( (A+C)+XX, (A*B+C*D)+X, B+D )</var></code></li>
<li><code><var>plus( (A+C)+XX, (A*B-C*D)+X, B*D )</var></code></li>
<li><code><var>plus( (A*C)+XX, (A*B-C*D)+X, B+D )</var></code></li>
<li><code><var>plus( (A+C)+XX, (A*B-C*D)+X, B+D )</var></code></li>
</ul>
</div>
</div>
<div class="hints">
<p data-if="SQUARE"><code>= <var>LEFT + RIGHT</var></code></p>
<p><code>= <var>plus( mult( A+X, RIGHT ), mult( B, RIGHT ) )</var></code></p>
<p><code>= <var>plus( parens( mult( A+X, C+X ) ), parens( mult( A+X, D ) ), parens( mult( B, C+X ) ), parens( mult( B, D ) ) )</var></code></p>
<p><code>= <var>plus( (A*C)+XX, parens( mult( A+X, D ) ), parens( mult( B, C+X ) ), parens( mult( B, D ) ) )</var></code></p>
<p><code>= <var>plus( (A*C)+XX, parens( plus( (A*D)+X, (B*C)+X ) ), parens( mult( B, D ) ) )</var></code></p>
<p><code>= <var>plus( (A*C)+XX, (A*D+B*C)+X, parens( mult( B, D ) ) )</var></code></p>
<p><code>= <var>plus( (A*C)+XX, (A*D+B*C)+X, B*D )</var></code></p>
</div>
</div>
</body>
</html>