Please help me understand and explain why it is that please

What is the answer to |-2x-5|-|-4+8| and x=7

The amount of money, in dollars, in an account after t years is given by a = 1000(1.03)^t. the initial deposit into the account was $_^a0 and the interest rate was _a1% per year. only enter numbers in the boxes. do not include any commas or decimal points^t. the initial deposit into the account was $__^a0 and the interest rate is % per year.

The measure of one angle of an octagon is two times smaller that of the other seven angles. what is the measure of each angle?