<!DOCTYPE html>
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8" />
<title>ГГ</title>
<style>
* {
margin:0;
padding: 0;
outline: none;
}
label {
display: block;
padding: 20px;
margin: 20px;
border: 1px solid red;
}
</style>
</head>
<body>
<select id="factor">
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
<!-- <option value="6">6</option>
<option value="7">7</option>
<option value="8">8</option>
<option value="9">9</option>
<option value="10">10</option>
<option value="11">11</option>
<option value="12">12</option>
<option value="13">13</option>
<option value="14">14</option>
<option value="15">15</option> -->
</select>
<label for="value">
Введите значение:
<input type="text" id="value">
</label>
<select id="year">
<!-- <option value="1990">1990</option>
<option value="1991">1991</option>
<option value="1992">1992</option>
<option value="1993">1993</option>
<option value="1994">1994</option>
<option value="1995">1995</option>
<option value="1996">1996</option>
<option value="1997">1997</option>
<option value="1998">1998</option>
<option value="1999">1999</option> -->
<option value="2000">2000</option>
<option value="2001">2001</option>
<option value="2002">2002</option>
<option value="2003">2003</option>
<option value="2004">2004</option>
<option value="2005">2005</option>
<option value="2006">2006</option>
<option value="2007">2007</option>
<option value="2008">2008</option>
<option value="2009">2009</option>
<option value="2010">2010</option>
<option value="2011">2011</option>
<option value="2012">2012</option>
<option value="2013">2013</option>
<option value="2014">2014</option>
</select>
<label for="result">Результат: <input type="text" id="result"></label>
<button>Получить результат</button>
<script>
var select1 = document.querySelector('#factor');
var select2 = document.querySelector('#year');
var valueElem = document.querySelector('#value');
var resultElem = document.querySelector('#result');
document.querySelector('button').onclick = function(){
var x = valueElem.value;
var n = select2.options[select2.options.selectedIndex].value - 2000;
var factor = select1.options[select1.options.selectedIndex].value;
if (factor == 1){
resultElem.value = Math.abs((6.13+0.3*n)*Math.log(x)-(42.60+3.7*n));
} else
if (factor == 2){
resultElem.value = Math.abs((3.054-0.7*n)*Math.log(x)-(18.022+16.205*n));
} else
if (factor == 3){
resultElem.value = Math.abs((0.6393+0.5*n)*Math.log(x)+(6.0756+15.6*n));
} else
if (factor == 4){
resultElem.value = Math.abs((8.4689+0.52*n)*Math.log(x)-(54.782+3.13*n));
} else
if (factor == 5){
resultElem.value = Math.abs((-1.578+0.635*n)*Math.log(x)+(28.168-6.472*n));
}
}
</script>
</body>
</html>