Question 100202
Using brackets helps visually, but nested parentheses are okay, too.

4[2(-5x+y)-y]-10(y-4x) means 4 * (2 * (-5x + y) - y) - 10*(y - 4x).

Then you simplify the innermost parentheses repeatedly. But you have to remember the rules of precedence: exponentiation, then multiplication and division (left to right), then addition and subtraction (left to right).


4 * (2 * (-5x + y) - y) - 10*(y - 4x) becomes
4 * (-10x + 2y - y) - 10*(y - 4x) because you do the multiplication before subtracting the y.

Solving inside the parentheses is next:

4 * (-10x + y) - 10*(y - 4x)

Now multiply left to right:

-40x + 4y - 10y + 40x because mutiplying -4x by -10 is +40x.

The -40x cancels + 40x, so we end up with -6y