Answer:
12m+4ns-8y
Explanation:
4(3m+sn-2y) is your equation.
You distribute the parenthesis, which gets you:
=4·3m+4sn+4(-2y)
You will then apply the subtraction (minus) sign to plus rules:
which is +(-a)=-a
which gets you:
=4·3m+4ns-4·2y
Once you simplify, it is:
12m+4ns-8y