var myElement = document.querySelector('.hello');
// set inline-style transform to element
myElement.style.transform = "translateX(" + (-200) + "px) scaleX(" + 1.6 + ") scaleY(" + 1.2 + ")";
function getTranslateX() {
var style = window.getComputedStyle(myElement);
var matrix = new WebKitCSSMatrix(style.transform);
console.log('translateX: ', matrix.m41);
}
document.querySelector('button').addEventListener('click', getTranslateX);