With negative numbers, how do we know when the negative sign indicates that it is a subtraction or it is a negative number? This is a question from Khan Academy:
(−5+7×1)−9×5
If you calculate the equation in the parentheses which equals 2, then the equation becomes 2-9x5. At this point, would you calculate the 9x5 part as 9 x 5 then subtract 2 or -9 x 5 then add 2. I know that this isn't the greatest example since it would equal -43 regardless but there are some equations where it would change the entire equation.

Design an er diagram for keeping track of information about votes taken in the u.s. house of representatives during the current two-year congressional session. the database needs to keep track of each u.s. state's name (e.g., texas', new york', california') and include the region of the state (whose domain is {northeast', midwest', southeast', southwest', west'}). each congress person in the house of representatives is described by his or her name, plus the district represented, the start date when the congressperson was first elected, and the political party to which he or she belongs (whose domain is {republican', democrat', 'independent', other'}). the database keeps track of each bill (i.e., proposed law), including the bill name, the date of vote on the bill, whether the bill passed or failed (whose domain is {yes', no'}), and the sponsor (the congressperson(s) who sponsored - that is, proposed - the bill). the database also keeps track of how each congressperson voted on each bill (domain of vote attribute is {yes', no', abstain', absent'}). additional information:

Rounded to the nearest tenth, what is the value of x

Aof 12 , we to a of 4 to on a .of 4 be ?