JavaScript - ¿como extraer el valor de cada select y sumar?

<form>

<select>

<option>2</option>

<option>5<option>

</select >

<select>

<option>7</option>

<option>2<option>

</select >

</form>

<form>

<select id="select1">

<option value="2">2</option>

<option value="5">5</option>

</select>

 +

<select id="select2">

<option value="7">7</option>

<option value="2">2</option>

</select>

<button type="button" onclick="test()">Suma</button>

</form>

<h2 id="result"></h2>

<script>

function test() {

var x =+ document.getElementById("select1").value;

var y =+ document.getElementById("select2").value;

document.getElementById("result").innerHTML = x + y;

}

</script>