how to solve this question quickly?

<p>z=x-y+4
z=y-w-3
z=w-x+5</p>

<p>Based on the system of questions above, what is the value of z?</p>

<p>a.) 2
b.) 3
c.) 4
d.) 6
e.) 12</p>

<p>Is there any fast way to solve this problem?</p>

<p>EDIT: .... lol wow I am tired tonight....</p>

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<p>just add all the equations together... ?</p>

<p>Dunno a shortcut but I was able to solve it quickly by just adding the equations .</p>

<p>Answer key says that its 2</p>

<p>Just add all 3 equations together. 3z = 6, z = 2</p>

<p>thanks! I was wondering thou cuz i have SAT on Saturday.</p>

<p>What's the most effective thing to do the day before the SAT test?
Should i relax, watch tv? should i review all the questions i got wrong on Collegeboard SAT?</p>

<p>Also, what are some recommendations for the essay portion of the SAT, aside from filling in the two pages? If you scored a 10 or higher, what do u do to get that score? I filled it up and i got 8 three times in a row.</p>

<p>more often that not, these system of equations question can be solved by either adding or subtracting the equations</p>

<p>For the day before the SAT, just take it easy, make sure you get a good amt of sleep, have all your materials packed and ready for you.</p>

<p>I didn't have any time to study the second time i took my SAT so I tried cramming the day before. My score dropped 10 points.</p>

<p>Luckily, my ACT made up for it :></p>