<script>

/**
 * @param {string} equation
 * @return {string}
 */
function solveEquation(equation) {
	var arr = equation.split("=");

	var lhs = arr[0],
	    rhs = arr[1];

	var lhsxcoeff, lhsconstant, rhsxcoeff, rhsconstant;

        // if LHS equals RHS
	if (lhs === rhs)
		return "Infinite solutions";

        // parse and extract lhs x coefficient and constant
	[lhsxcoeff, lhsconstant] = parse(lhs);

        // parse and extract rhs x coefficient and constant
	[rhsxcoeff, rhsconstant] = parse(rhs);

        // compute the final x coefficient by substracting RHS x coeff. from LHS x coeff.
	var finalXcoeff = lhsxcoeff - rhsxcoeff;

        // if the RHS and LHS coeffcients and constants match respectively
	if (lhsxcoeff === rhsxcoeff && lhsconstant === rhsconstant)
		return "Infinite solutions";
 
        // if there is no final x coefficient left say for e.g. in equations like x = x + 2;
	if (finalXcoeff === 0)
		return "No solution";

        // final case compute the value of x
	if (finalXcoeff >= 1 || finalXcoeff < 0) {
		return 'x=' + ((rhsconstant - lhsconstant) / finalXcoeff);
	}
};

// parse equation (LHS and RHS) using regex
function parse(expression) {
	var arr = expression.match(/-?(\d*x|\d+)/g);
	var finalXCoefficient = 0;
	var constantSum = 0;

	for (var i = 0; i < arr.length; i++) {
		if (arr[i].match(/x/g)) {
			var xcoefficient = arr[i].substring(0, arr[i].length - 1);
			if (xcoefficient === '-')
				xcoefficient = -1;

			if (xcoefficient === '')
				xcoefficient = 1;

			finalXCoefficient += parseInt(xcoefficient);
		} else
			constantSum += parseInt(arr[i]);
	}

	return [finalXCoefficient, constantSum];
}


document.write(solveEquation("x+5-3+x=6+x-2")+'<br/>');
document.write(solveEquation("x=x")+'<br/>');
document.write(solveEquation("2x=x")+'<br/>');
document.write(solveEquation("2x+3x-6x=x+2")+'<br/>');
document.write(solveEquation("x=x+2")+'<br/>');

</script>