Simplify, using order of operations:
81 -2[5(3+4)]

5

Step-by-step explanation:

Let's work from the middle of the equation to the outside of it. Our first part of the equation is 3+4, which equals seven, so we have the equation:

81-2[5(7)]

Then, we multiply 5 and 7, which is 35, so we get the equation:

81-2[35]

Then we have -2 outside of the brackets, so we can multiply -2 and 35, which is -75, so we have the equation:

81-75

Which is 5.

~Stay golden~ :)

your answer would be 10x - 1