jQuery:
var scale_width = 1;
var scale_height = 1.5;
$(".english_canvas.unit_11").css("transform","scale('"+scale_width+"','"+scale_height+"')");
HTML:
<div style="width: 210px; height: 210px; background-color: #fff" class="english_canvas unit_11"></div>
"scale(" + scale_width+", " + scale_height+")"is enough. Don't enclose scale values in''.