Question 1182387
if the given number is 3a, then twice the given number is 2 * 3 * a = 6 * a = 6a


keep in mind that 3a is really a short hand version of 3 * a, where * is the multiplication symbol.


twice * 3a is 2 * 3a which is 2 * 3 * a.


based on the asociative law of multiplication, 2 * 3 * a is equivalent to 2 * (3 * a) and also equivalent to (2 * 3) * a.


in that last form, it becomes 6 * a which becomes 6a when shown in the shorthand notation.


here's a reference on the associative law of addition and multiplication.


<a href = "https://www.britannica.com/science/associative-law" target = "_blank">https://www.britannica.com/science/associative-law</a>