couple math question

Test Preparation SAT Preparation
1

<p>The figure above shows part of the graph of the quadratic function f. the graph intersects the x-axis at x = -1 and at x = k. if the vertex of the graph of f is point (3,-4), what is the value of k?</p>

<p>[ to solve this dont i just foil (x+1)(x-k) and then plug in 3 for x and make the equation equal to -4?]</p>

<p>of all the apartments in an apartment building, 20 percent are single-bedroom apartments, and 30 percent of the single-bedroom apartments have balconies. if 28 single-bedroom apartments do not have balconies, how many apartments are there in this apartment building?</p>

<p>[no clue how to solve this! lol]</p>

2

<p>I think k is just 7 because the vertex is at x=3, so the distance from -1 to 3 should be the same as the distance from 3 to k.</p>

3

<p>hahaha wooooooow!!! i forgot that simple rule i guess you can say, thank you!</p>

4

<p>No problem. Is the next one 200? If so:
Let x = the total number of apartments which is the solution
(1/5)<em>x= the number of single bedroom apartments
(3/10) * [(1/5)</em>x] = the number of single bed apartments with balconies, so
[1-(3/10)] * [(1/5)*x] = single bed apartments without balconies, which is 28 SO
(7/10) * (x/5) = 28</p>

5

<p>oooo i see now, thank you again!!</p>